cargo install fails with Self struct constructors are unstable

[maxwell-k]

I've been happily using v0.4.0 since it came out (great project!) but when I try to build a more recent version (e.g. v0.4.1. or v0.5.0), cargo fails with an error:

error[E0658]: `Self` struct constructors are unstable (see issue #51994)                                                                               
  --> /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/comrak-0.4.1/src/html.rs:73:9                                                      
   |                                                                                                                                                   
73 |         Self(HashSet::new())                                                                                                                      
   |         ^^^^                                                                                                                        

The issue mentioned in the error message doesn't help me avoid this.

Detailed output from attempting to install v0.4.1 is below:

$ cargo install comrak --force --verbose --version 0.4.1
    Updating crates.io index
  Installing comrak v0.4.1                                                                                                                             
   Compiling proc-macro2 v0.4.27                                                                                                                       
   Compiling unicode-xid v0.1.0                                                                                                                        
     Running `rustc --crate-name unicode_xid /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/unicode-xid-0.1.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' -C metadata=5fa0ac7939e7f58b -C extra-filename=-5fa0ac7939e7f58b --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/proc-macro2-0.4.27/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="proc-macro"' -C metadata=495c354e6dc247ee -C extra-filename=-495c354e6dc247ee --out-dir /tmp/cargo-installWCrlbH/release/build/proc-macro2-495c354e6dc247ee -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling memchr v2.2.0                                                                                                                             
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/memchr-2.2.0/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=2e508fcc9fcb9c8e -C extra-filename=-2e508fcc9fcb9c8e --out-dir /tmp/cargo-installWCrlbH/release/build/memchr-2e508fcc9fcb9c8e -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling libc v0.2.51                                                                                                                              
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/libc-0.2.51/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=2fc61d8b507411a9 -C extra-filename=-2fc61d8b507411a9 --out-dir /tmp/cargo-installWCrlbH/release/build/libc-2fc61d8b507411a9 -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling syn v0.15.30                                                                                                                              
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/syn-0.15.30/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="proc-macro2"' --cfg 'feature="quote"' -C metadata=105c6bc62a486db1 -C extra-filename=-105c6bc62a486db1 --out-dir /tmp/cargo-installWCrlbH/release/build/syn-105c6bc62a486db1 -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling ucd-trie v0.1.1                                                                                                                           
     Running `rustc --crate-name ucd_trie /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/ucd-trie-0.1.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="std"' -C metadata=0a8930e81bcc380c -C extra-filename=-0a8930e81bcc380c --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling maplit v1.0.1                                                                                                                             
     Running `rustc --crate-name maplit /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/maplit-1.0.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=a684fcefacdfafa4 -C extra-filename=-a684fcefacdfafa4 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling lazy_static v1.3.0                                                                                                                        
     Running `rustc --crate-name lazy_static /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/lazy_static-1.3.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=2af91ade475ddbea -C extra-filename=-2af91ade475ddbea --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling regex v1.1.5                                                                                                                              
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/regex-1.1.5/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=69a87108daf6f222 -C extra-filename=-69a87108daf6f222 --out-dir /tmp/cargo-installWCrlbH/release/build/regex-69a87108daf6f222 -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling ucd-util v0.1.3                                                                                                                           
     Running `rustc --crate-name ucd_util /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/ucd-util-0.1.3/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=2b6cee58fbae93f3 -C extra-filename=-2b6cee58fbae93f3 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling unicode-width v0.1.5                                                                                                                      
     Running `rustc --crate-name unicode_width /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/unicode-width-0.1.5/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' -C metadata=7df78f120c55f0bb -C extra-filename=-7df78f120c55f0bb --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling strsim v0.8.0                                                                                                                             
     Running `rustc --crate-name strsim /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/strsim-0.8.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=59c006ec0acf9452 -C extra-filename=-59c006ec0acf9452 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling vec_map v0.8.1                                                                                                                            
     Running `rustc --crate-name vec_map /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/vec_map-0.8.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=b7c280ce443eb023 -C extra-filename=-b7c280ce443eb023 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling bitflags v1.0.4                                                                                                                           
     Running `rustc --crate-name bitflags /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/bitflags-1.0.4/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' -C metadata=ad9a4cd6860446df -C extra-filename=-ad9a4cd6860446df --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling utf8-ranges v1.0.2                                                                                                                        
     Running `rustc --crate-name utf8_ranges /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/utf8-ranges-1.0.2/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=bb77f0491ef1334f -C extra-filename=-bb77f0491ef1334f --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling ansi_term v0.11.0                                                                                                                         
     Running `rustc --crate-name ansi_term /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/ansi_term-0.11.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=63e4b5a8d696310e -C extra-filename=-63e4b5a8d696310e --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling entities v1.0.1                                                                                                                           
     Running `rustc --crate-name entities /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/entities-1.0.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=b41079d2b7f63e1a -C extra-filename=-b41079d2b7f63e1a --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling typed-arena v1.4.1                                                                                                                        
     Running `rustc --crate-name typed_arena /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/typed-arena-1.4.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="std"' -C metadata=79fb06894b14b115 -C extra-filename=-79fb06894b14b115 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
   Compiling unicode_categories v0.1.1                                                                                                                 
     Running `rustc --crate-name unicode_categories /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/unicode_categories-0.1.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=769eb0b437b32a41 -C extra-filename=-769eb0b437b32a41 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow`
     Running `/tmp/cargo-installWCrlbH/release/build/proc-macro2-495c354e6dc247ee/build-script-build`                                                  
     Running `/tmp/cargo-installWCrlbH/release/build/memchr-2e508fcc9fcb9c8e/build-script-build`                                                       
     Running `/tmp/cargo-installWCrlbH/release/build/libc-2fc61d8b507411a9/build-script-build`                                                         
     Running `/tmp/cargo-installWCrlbH/release/build/syn-105c6bc62a486db1/build-script-build`                                                          
   Compiling thread_local v0.3.6                                                                                                                       
     Running `rustc --crate-name thread_local /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/thread_local-0.3.6/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=d1b4db2b6473a0ca -C extra-filename=-d1b4db2b6473a0ca --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern lazy_static=/tmp/cargo-installWCrlbH/release/deps/liblazy_static-2af91ade475ddbea.rlib --cap-lints allow`
   Compiling pest v2.1.0                                                                                                                               
     Running `rustc --crate-name pest /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/pest-2.1.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=1af1081016174dd9 -C extra-filename=-1af1081016174dd9 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern ucd_trie=/tmp/cargo-installWCrlbH/release/deps/libucd_trie-0a8930e81bcc380c.rlib --cap-lints allow`
   Compiling regex-syntax v0.6.6                                                                                                                       
     Running `rustc --crate-name regex_syntax /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/regex-syntax-0.6.6/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=a14773b79df04db2 -C extra-filename=-a14773b79df04db2 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern ucd_util=/tmp/cargo-installWCrlbH/release/deps/libucd_util-2b6cee58fbae93f3.rlib --cap-lints allow`
   Compiling textwrap v0.11.0                                                                                                                          
     Running `rustc --crate-name textwrap /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/textwrap-0.11.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=23e5657108be28e4 -C extra-filename=-23e5657108be28e4 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern unicode_width=/tmp/cargo-installWCrlbH/release/deps/libunicode_width-7df78f120c55f0bb.rlib --cap-lints allow`
     Running `/tmp/cargo-installWCrlbH/release/build/regex-69a87108daf6f222/build-script-build`                                                        
     Running `rustc --crate-name proc_macro2 /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/proc-macro2-0.4.27/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="proc-macro"' -C metadata=794e7ca0e6b37112 -C extra-filename=-794e7ca0e6b37112 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern unicode_xid=/tmp/cargo-installWCrlbH/release/deps/libunicode_xid-5fa0ac7939e7f58b.rlib --cap-lints allow --cfg u128 --cfg use_proc_macro --cfg wrap_proc_macro`
     Running `rustc --crate-name memchr /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/memchr-2.2.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=2d1b3fe3e2e1d5a8 -C extra-filename=-2d1b3fe3e2e1d5a8 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow --cfg memchr_runtime_simd --cfg memchr_runtime_sse2 --cfg memchr_runtime_sse42 --cfg memchr_runtime_avx`
     Running `rustc --crate-name libc /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/libc-0.2.51/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=2d528faf9bce9082 -C extra-filename=-2d528faf9bce9082 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --cap-lints allow --cfg libc_priv_mod_use --cfg libc_union --cfg libc_const_size_of --cfg libc_align --cfg libc_core_cvoid`
   Compiling pest_meta v2.1.0                                                                                                                          
     Running `rustc --crate-name pest_meta /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/pest_meta-2.1.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=39924b3d7be8326b -C extra-filename=-39924b3d7be8326b --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern maplit=/tmp/cargo-installWCrlbH/release/deps/libmaplit-a684fcefacdfafa4.rlib --extern pest=/tmp/cargo-installWCrlbH/release/deps/libpest-1af1081016174dd9.rlib --cap-lints allow`
   Compiling quote v0.6.11                                                                                                                             
     Running `rustc --crate-name quote /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/quote-0.6.11/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="proc-macro"' --cfg 'feature="proc-macro2"' -C metadata=5679acc1c47b5be4 -C extra-filename=-5679acc1c47b5be4 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern proc_macro2=/tmp/cargo-installWCrlbH/release/deps/libproc_macro2-794e7ca0e6b37112.rlib --cap-lints allow`
   Compiling aho-corasick v0.7.3                                                                                                                       
     Running `rustc --crate-name aho_corasick /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/aho-corasick-0.7.3/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="memchr"' --cfg 'feature="std"' -C metadata=0b53d6479b2f16e8 -C extra-filename=-0b53d6479b2f16e8 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern memchr=/tmp/cargo-installWCrlbH/release/deps/libmemchr-2d1b3fe3e2e1d5a8.rlib --cap-lints allow`
   Compiling twoway v0.1.8                                                                                                                             
     Running `rustc --crate-name twoway /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/twoway-0.1.8/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="memchr"' --cfg 'feature="use_std"' -C metadata=445ae107fc8ff1ce -C extra-filename=-445ae107fc8ff1ce --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern memchr=/tmp/cargo-installWCrlbH/release/deps/libmemchr-2d1b3fe3e2e1d5a8.rlib --cap-lints allow`
   Compiling atty v0.2.11                                                                                                                              
     Running `rustc --crate-name atty /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/atty-0.2.11/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=bd2cd300897e4da9 -C extra-filename=-bd2cd300897e4da9 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern libc=/tmp/cargo-installWCrlbH/release/deps/liblibc-2d528faf9bce9082.rlib --cap-lints allow`
     Running `rustc --crate-name regex /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/regex-1.1.5/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=c8d2be83cc7ee0e8 -C extra-filename=-c8d2be83cc7ee0e8 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern aho_corasick=/tmp/cargo-installWCrlbH/release/deps/libaho_corasick-0b53d6479b2f16e8.rlib --extern memchr=/tmp/cargo-installWCrlbH/release/deps/libmemchr-2d1b3fe3e2e1d5a8.rlib --extern regex_syntax=/tmp/cargo-installWCrlbH/release/deps/libregex_syntax-a14773b79df04db2.rlib --extern thread_local=/tmp/cargo-installWCrlbH/release/deps/libthread_local-d1b4db2b6473a0ca.rlib --extern utf8_ranges=/tmp/cargo-installWCrlbH/release/deps/libutf8_ranges-bb77f0491ef1334f.rlib --cap-lints allow --cfg regex_runtime_teddy_ssse3 --cfg regex_runtime_teddy_avx2`
   Compiling clap v2.33.0                                                                                                                              
     Running `rustc --crate-name clap /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/clap-2.33.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="ansi_term"' --cfg 'feature="atty"' --cfg 'feature="color"' --cfg 'feature="default"' --cfg 'feature="strsim"' --cfg 'feature="suggestions"' --cfg 'feature="vec_map"' -C metadata=1677959eed09ed9b -C extra-filename=-1677959eed09ed9b --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern ansi_term=/tmp/cargo-installWCrlbH/release/deps/libansi_term-63e4b5a8d696310e.rlib --extern atty=/tmp/cargo-installWCrlbH/release/deps/libatty-bd2cd300897e4da9.rlib --extern bitflags=/tmp/cargo-installWCrlbH/release/deps/libbitflags-ad9a4cd6860446df.rlib --extern strsim=/tmp/cargo-installWCrlbH/release/deps/libstrsim-59c006ec0acf9452.rlib --extern textwrap=/tmp/cargo-installWCrlbH/release/deps/libtextwrap-23e5657108be28e4.rlib --extern unicode_width=/tmp/cargo-installWCrlbH/release/deps/libunicode_width-7df78f120c55f0bb.rlib --extern vec_map=/tmp/cargo-installWCrlbH/release/deps/libvec_map-b7c280ce443eb023.rlib --cap-lints allow`
     Running `rustc --crate-name syn /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/syn-0.15.30/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="proc-macro2"' --cfg 'feature="quote"' -C metadata=5a5d7ba553291088 -C extra-filename=-5a5d7ba553291088 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern proc_macro2=/tmp/cargo-installWCrlbH/release/deps/libproc_macro2-794e7ca0e6b37112.rlib --extern quote=/tmp/cargo-installWCrlbH/release/deps/libquote-5679acc1c47b5be4.rlib --extern unicode_xid=/tmp/cargo-installWCrlbH/release/deps/libunicode_xid-5fa0ac7939e7f58b.rlib --cap-lints allow --cfg syn_can_use_thread_id --cfg syn_can_call_macro_by_path --cfg syn_disable_nightly_tests`
   Compiling pest_generator v2.1.0                                                                                                                     
     Running `rustc --crate-name pest_generator /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/pest_generator-2.1.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=16ba334e3366017b -C extra-filename=-16ba334e3366017b --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern pest=/tmp/cargo-installWCrlbH/release/deps/libpest-1af1081016174dd9.rlib --extern pest_meta=/tmp/cargo-installWCrlbH/release/deps/libpest_meta-39924b3d7be8326b.rlib --extern proc_macro2=/tmp/cargo-installWCrlbH/release/deps/libproc_macro2-794e7ca0e6b37112.rlib --extern quote=/tmp/cargo-installWCrlbH/release/deps/libquote-5679acc1c47b5be4.rlib --extern syn=/tmp/cargo-installWCrlbH/release/deps/libsyn-5a5d7ba553291088.rlib --cap-lints allow`
   Compiling pest_derive v2.1.0                                                                                                                        
     Running `rustc --crate-name pest_derive /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/pest_derive-2.1.0/src/lib.rs --color always --crate-type proc-macro --emit=dep-info,link -C prefer-dynamic -C opt-level=3 -C metadata=9d1e413f5b3f6f9e -C extra-filename=-9d1e413f5b3f6f9e --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern pest=/tmp/cargo-installWCrlbH/release/deps/libpest-1af1081016174dd9.rlib --extern pest_generator=/tmp/cargo-installWCrlbH/release/deps/libpest_generator-16ba334e3366017b.rlib --cap-lints allow`
   Compiling comrak v0.4.1                                                                                                                             
     Running `rustc --crate-name comrak /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/comrak-0.4.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="clap"' --cfg 'feature="default"' -C metadata=ec076ac8ea28c990 -C extra-filename=-ec076ac8ea28c990 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern clap=/tmp/cargo-installWCrlbH/release/deps/libclap-1677959eed09ed9b.rlib --extern entities=/tmp/cargo-installWCrlbH/release/deps/libentities-b41079d2b7f63e1a.rlib --extern lazy_static=/tmp/cargo-installWCrlbH/release/deps/liblazy_static-2af91ade475ddbea.rlib --extern pest=/tmp/cargo-installWCrlbH/release/deps/libpest-1af1081016174dd9.rlib --extern pest_derive=/tmp/cargo-installWCrlbH/release/deps/libpest_derive-9d1e413f5b3f6f9e.so --extern regex=/tmp/cargo-installWCrlbH/release/deps/libregex-c8d2be83cc7ee0e8.rlib --extern twoway=/tmp/cargo-installWCrlbH/release/deps/libtwoway-445ae107fc8ff1ce.rlib --extern typed_arena=/tmp/cargo-installWCrlbH/release/deps/libtyped_arena-79fb06894b14b115.rlib --extern unicode_categories=/tmp/cargo-installWCrlbH/release/deps/libunicode_categories-769eb0b437b32a41.rlib --cap-lints allow`
error[E0658]: `Self` struct constructors are unstable (see issue #51994)                                                                               
  --> /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/comrak-0.4.1/src/html.rs:73:9                                                      
   |                                                                                                                                                   
73 |         Self(HashSet::new())                                                                                                                      
   |         ^^^^                                                                                                                                      
                                                                                                                                                       
error: aborting due to previous error                                                                                                                  
                                                                                                                                                       
For more information about this error, try `rustc --explain E0658`.                                                                                    
error: failed to compile `comrak v0.4.1`, intermediate artifacts can be found at `/tmp/cargo-installWCrlbH`                                            

Caused by:
  Could not compile `comrak`.

Caused by:
  process didn't exit successfully: `rustc --crate-name comrak /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/comrak-0.4.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="clap"' --cfg 'feature="default"' -C metadata=ec076ac8ea28c990 -C extra-filename=-ec076ac8ea28c990 --out-dir /tmp/cargo-installWCrlbH/release/deps -L dependency=/tmp/cargo-installWCrlbH/release/deps --extern clap=/tmp/cargo-installWCrlbH/release/deps/libclap-1677959eed09ed9b.rlib --extern entities=/tmp/cargo-installWCrlbH/release/deps/libentities-b41079d2b7f63e1a.rlib --extern lazy_static=/tmp/cargo-installWCrlbH/release/deps/liblazy_static-2af91ade475ddbea.rlib --extern pest=/tmp/cargo-installWCrlbH/release/deps/libpest-1af1081016174dd9.rlib --extern pest_derive=/tmp/cargo-installWCrlbH/release/deps/libpest_derive-9d1e413f5b3f6f9e.so --extern regex=/tmp/cargo-installWCrlbH/release/deps/libregex-c8d2be83cc7ee0e8.rlib --extern twoway=/tmp/cargo-installWCrlbH/release/deps/libtwoway-445ae107fc8ff1ce.rlib --extern typed_arena=/tmp/cargo-installWCrlbH/release/deps/libtyped_arena-79fb06894b14b115.rlib --extern unicode_categories=/tmp/cargo-installWCrlbH/release/deps/libunicode_categories-769eb0b437b32a41.rlib --cap-lints allow` (exit code: 1)

Detailed output from attempting to install v0.5.0 is below:

$ cargo install comrak --force --verbose --version 0.5.0
    Updating crates.io index
  Installing comrak v0.5.0                                                                                                                             
   Compiling proc-macro2 v0.4.27                                                                                                                       
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/proc-macro2-0.4.27/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="proc-macro"' -C metadata=495c354e6dc247ee -C extra-filename=-495c354e6dc247ee --out-dir /tmp/cargo-installnrFCmC/release/build/proc-macro2-495c354e6dc247ee -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling unicode-xid v0.1.0                                                                                                                        
     Running `rustc --crate-name unicode_xid /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/unicode-xid-0.1.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' -C metadata=5fa0ac7939e7f58b -C extra-filename=-5fa0ac7939e7f58b --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling syn v0.15.30                                                                                                                              
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/syn-0.15.30/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="proc-macro2"' --cfg 'feature="quote"' -C metadata=105c6bc62a486db1 -C extra-filename=-105c6bc62a486db1 --out-dir /tmp/cargo-installnrFCmC/release/build/syn-105c6bc62a486db1 -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling memchr v2.2.0                                                                                                                             
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/memchr-2.2.0/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=2e508fcc9fcb9c8e -C extra-filename=-2e508fcc9fcb9c8e --out-dir /tmp/cargo-installnrFCmC/release/build/memchr-2e508fcc9fcb9c8e -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling ucd-trie v0.1.1                                                                                                                           
     Running `rustc --crate-name ucd_trie /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/ucd-trie-0.1.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="std"' -C metadata=0a8930e81bcc380c -C extra-filename=-0a8930e81bcc380c --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling libc v0.2.51                                                                                                                              
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/libc-0.2.51/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=2fc61d8b507411a9 -C extra-filename=-2fc61d8b507411a9 --out-dir /tmp/cargo-installnrFCmC/release/build/libc-2fc61d8b507411a9 -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling maplit v1.0.1                                                                                                                             
     Running `rustc --crate-name maplit /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/maplit-1.0.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=a684fcefacdfafa4 -C extra-filename=-a684fcefacdfafa4 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling unicode-width v0.1.5                                                                                                                      
     Running `rustc --crate-name unicode_width /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/unicode-width-0.1.5/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' -C metadata=7df78f120c55f0bb -C extra-filename=-7df78f120c55f0bb --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling ucd-util v0.1.3                                                                                                                           
     Running `rustc --crate-name ucd_util /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/ucd-util-0.1.3/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=2b6cee58fbae93f3 -C extra-filename=-2b6cee58fbae93f3 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling lazy_static v1.3.0                                                                                                                        
     Running `rustc --crate-name lazy_static /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/lazy_static-1.3.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=2af91ade475ddbea -C extra-filename=-2af91ade475ddbea --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling regex v1.1.5                                                                                                                              
     Running `rustc --crate-name build_script_build /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/regex-1.1.5/build.rs --color always --crate-type bin --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=69a87108daf6f222 -C extra-filename=-69a87108daf6f222 --out-dir /tmp/cargo-installnrFCmC/release/build/regex-69a87108daf6f222 -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling bitflags v1.0.4                                                                                                                           
     Running `rustc --crate-name bitflags /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/bitflags-1.0.4/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' -C metadata=ad9a4cd6860446df -C extra-filename=-ad9a4cd6860446df --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling strsim v0.8.0                                                                                                                             
     Running `rustc --crate-name strsim /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/strsim-0.8.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=59c006ec0acf9452 -C extra-filename=-59c006ec0acf9452 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling vec_map v0.8.1                                                                                                                            
     Running `rustc --crate-name vec_map /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/vec_map-0.8.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=b7c280ce443eb023 -C extra-filename=-b7c280ce443eb023 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling utf8-ranges v1.0.2                                                                                                                        
     Running `rustc --crate-name utf8_ranges /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/utf8-ranges-1.0.2/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=bb77f0491ef1334f -C extra-filename=-bb77f0491ef1334f --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling ansi_term v0.11.0                                                                                                                         
     Running `rustc --crate-name ansi_term /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/ansi_term-0.11.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=63e4b5a8d696310e -C extra-filename=-63e4b5a8d696310e --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling unicode_categories v0.1.1                                                                                                                 
     Running `rustc --crate-name unicode_categories /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/unicode_categories-0.1.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=769eb0b437b32a41 -C extra-filename=-769eb0b437b32a41 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling typed-arena v1.4.1                                                                                                                        
     Running `rustc --crate-name typed_arena /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/typed-arena-1.4.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="std"' -C metadata=79fb06894b14b115 -C extra-filename=-79fb06894b14b115 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
   Compiling entities v1.0.1                                                                                                                           
     Running `rustc --crate-name entities /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/entities-1.0.1/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=b41079d2b7f63e1a -C extra-filename=-b41079d2b7f63e1a --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow`
     Running `/tmp/cargo-installnrFCmC/release/build/proc-macro2-495c354e6dc247ee/build-script-build`                                                  
     Running `/tmp/cargo-installnrFCmC/release/build/syn-105c6bc62a486db1/build-script-build`                                                          
     Running `/tmp/cargo-installnrFCmC/release/build/memchr-2e508fcc9fcb9c8e/build-script-build`                                                       
   Compiling pest v2.1.0                                                                                                                               
     Running `rustc --crate-name pest /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/pest-2.1.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=1af1081016174dd9 -C extra-filename=-1af1081016174dd9 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern ucd_trie=/tmp/cargo-installnrFCmC/release/deps/libucd_trie-0a8930e81bcc380c.rlib --cap-lints allow`
   Compiling textwrap v0.11.0                                                                                                                          
     Running `rustc --crate-name textwrap /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/textwrap-0.11.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=23e5657108be28e4 -C extra-filename=-23e5657108be28e4 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern unicode_width=/tmp/cargo-installnrFCmC/release/deps/libunicode_width-7df78f120c55f0bb.rlib --cap-lints allow`
   Compiling regex-syntax v0.6.6                                                                                                                       
     Running `rustc --crate-name regex_syntax /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/regex-syntax-0.6.6/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=a14773b79df04db2 -C extra-filename=-a14773b79df04db2 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern ucd_util=/tmp/cargo-installnrFCmC/release/deps/libucd_util-2b6cee58fbae93f3.rlib --cap-lints allow`
   Compiling thread_local v0.3.6                                                                                                                       
     Running `rustc --crate-name thread_local /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/thread_local-0.3.6/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=d1b4db2b6473a0ca -C extra-filename=-d1b4db2b6473a0ca --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern lazy_static=/tmp/cargo-installnrFCmC/release/deps/liblazy_static-2af91ade475ddbea.rlib --cap-lints allow`
     Running `/tmp/cargo-installnrFCmC/release/build/libc-2fc61d8b507411a9/build-script-build`                                                         
     Running `/tmp/cargo-installnrFCmC/release/build/regex-69a87108daf6f222/build-script-build`                                                        
     Running `rustc --crate-name proc_macro2 /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/proc-macro2-0.4.27/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="proc-macro"' -C metadata=794e7ca0e6b37112 -C extra-filename=-794e7ca0e6b37112 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern unicode_xid=/tmp/cargo-installnrFCmC/release/deps/libunicode_xid-5fa0ac7939e7f58b.rlib --cap-lints allow --cfg u128 --cfg use_proc_macro --cfg wrap_proc_macro`
     Running `rustc --crate-name memchr /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/memchr-2.2.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=2d1b3fe3e2e1d5a8 -C extra-filename=-2d1b3fe3e2e1d5a8 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow --cfg memchr_runtime_simd --cfg memchr_runtime_sse2 --cfg memchr_runtime_sse42 --cfg memchr_runtime_avx`
   Compiling pest_meta v2.1.0                                                                                                                          
     Running `rustc --crate-name pest_meta /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/pest_meta-2.1.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=39924b3d7be8326b -C extra-filename=-39924b3d7be8326b --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern maplit=/tmp/cargo-installnrFCmC/release/deps/libmaplit-a684fcefacdfafa4.rlib --extern pest=/tmp/cargo-installnrFCmC/release/deps/libpest-1af1081016174dd9.rlib --cap-lints allow`
     Running `rustc --crate-name libc /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/libc-0.2.51/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=2d528faf9bce9082 -C extra-filename=-2d528faf9bce9082 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --cap-lints allow --cfg libc_priv_mod_use --cfg libc_union --cfg libc_const_size_of --cfg libc_align --cfg libc_core_cvoid`
   Compiling quote v0.6.11                                                                                                                             
     Running `rustc --crate-name quote /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/quote-0.6.11/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="proc-macro"' --cfg 'feature="proc-macro2"' -C metadata=5679acc1c47b5be4 -C extra-filename=-5679acc1c47b5be4 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern proc_macro2=/tmp/cargo-installnrFCmC/release/deps/libproc_macro2-794e7ca0e6b37112.rlib --cap-lints allow`
   Compiling aho-corasick v0.7.3                                                                                                                       
     Running `rustc --crate-name aho_corasick /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/aho-corasick-0.7.3/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="memchr"' --cfg 'feature="std"' -C metadata=0b53d6479b2f16e8 -C extra-filename=-0b53d6479b2f16e8 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern memchr=/tmp/cargo-installnrFCmC/release/deps/libmemchr-2d1b3fe3e2e1d5a8.rlib --cap-lints allow`
   Compiling twoway v0.1.8                                                                                                                             
     Running `rustc --crate-name twoway /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/twoway-0.1.8/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="memchr"' --cfg 'feature="use_std"' -C metadata=445ae107fc8ff1ce -C extra-filename=-445ae107fc8ff1ce --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern memchr=/tmp/cargo-installnrFCmC/release/deps/libmemchr-2d1b3fe3e2e1d5a8.rlib --cap-lints allow`
   Compiling atty v0.2.11                                                                                                                              
     Running `rustc --crate-name atty /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/atty-0.2.11/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=bd2cd300897e4da9 -C extra-filename=-bd2cd300897e4da9 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern libc=/tmp/cargo-installnrFCmC/release/deps/liblibc-2d528faf9bce9082.rlib --cap-lints allow`
     Running `rustc --crate-name syn /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/syn-0.15.30/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="proc-macro2"' --cfg 'feature="quote"' -C metadata=5a5d7ba553291088 -C extra-filename=-5a5d7ba553291088 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern proc_macro2=/tmp/cargo-installnrFCmC/release/deps/libproc_macro2-794e7ca0e6b37112.rlib --extern quote=/tmp/cargo-installnrFCmC/release/deps/libquote-5679acc1c47b5be4.rlib --extern unicode_xid=/tmp/cargo-installnrFCmC/release/deps/libunicode_xid-5fa0ac7939e7f58b.rlib --cap-lints allow --cfg syn_can_use_thread_id --cfg syn_can_call_macro_by_path --cfg syn_disable_nightly_tests`
     Running `rustc --crate-name regex /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/regex-1.1.5/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="default"' --cfg 'feature="use_std"' -C metadata=c8d2be83cc7ee0e8 -C extra-filename=-c8d2be83cc7ee0e8 --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern aho_corasick=/tmp/cargo-installnrFCmC/release/deps/libaho_corasick-0b53d6479b2f16e8.rlib --extern memchr=/tmp/cargo-installnrFCmC/release/deps/libmemchr-2d1b3fe3e2e1d5a8.rlib --extern regex_syntax=/tmp/cargo-installnrFCmC/release/deps/libregex_syntax-a14773b79df04db2.rlib --extern thread_local=/tmp/cargo-installnrFCmC/release/deps/libthread_local-d1b4db2b6473a0ca.rlib --extern utf8_ranges=/tmp/cargo-installnrFCmC/release/deps/libutf8_ranges-bb77f0491ef1334f.rlib --cap-lints allow --cfg regex_runtime_teddy_ssse3 --cfg regex_runtime_teddy_avx2`
   Compiling clap v2.33.0                                                                                                                              
     Running `rustc --crate-name clap /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/clap-2.33.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="ansi_term"' --cfg 'feature="atty"' --cfg 'feature="color"' --cfg 'feature="default"' --cfg 'feature="strsim"' --cfg 'feature="suggestions"' --cfg 'feature="vec_map"' -C metadata=1677959eed09ed9b -C extra-filename=-1677959eed09ed9b --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern ansi_term=/tmp/cargo-installnrFCmC/release/deps/libansi_term-63e4b5a8d696310e.rlib --extern atty=/tmp/cargo-installnrFCmC/release/deps/libatty-bd2cd300897e4da9.rlib --extern bitflags=/tmp/cargo-installnrFCmC/release/deps/libbitflags-ad9a4cd6860446df.rlib --extern strsim=/tmp/cargo-installnrFCmC/release/deps/libstrsim-59c006ec0acf9452.rlib --extern textwrap=/tmp/cargo-installnrFCmC/release/deps/libtextwrap-23e5657108be28e4.rlib --extern unicode_width=/tmp/cargo-installnrFCmC/release/deps/libunicode_width-7df78f120c55f0bb.rlib --extern vec_map=/tmp/cargo-installnrFCmC/release/deps/libvec_map-b7c280ce443eb023.rlib --cap-lints allow`
   Compiling pest_generator v2.1.0                                                                                                                     
     Running `rustc --crate-name pest_generator /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/pest_generator-2.1.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 -C metadata=16ba334e3366017b -C extra-filename=-16ba334e3366017b --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern pest=/tmp/cargo-installnrFCmC/release/deps/libpest-1af1081016174dd9.rlib --extern pest_meta=/tmp/cargo-installnrFCmC/release/deps/libpest_meta-39924b3d7be8326b.rlib --extern proc_macro2=/tmp/cargo-installnrFCmC/release/deps/libproc_macro2-794e7ca0e6b37112.rlib --extern quote=/tmp/cargo-installnrFCmC/release/deps/libquote-5679acc1c47b5be4.rlib --extern syn=/tmp/cargo-installnrFCmC/release/deps/libsyn-5a5d7ba553291088.rlib --cap-lints allow`
   Compiling pest_derive v2.1.0                                                                                                                        
     Running `rustc --crate-name pest_derive /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/pest_derive-2.1.0/src/lib.rs --color always --crate-type proc-macro --emit=dep-info,link -C prefer-dynamic -C opt-level=3 -C metadata=9d1e413f5b3f6f9e -C extra-filename=-9d1e413f5b3f6f9e --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern pest=/tmp/cargo-installnrFCmC/release/deps/libpest-1af1081016174dd9.rlib --extern pest_generator=/tmp/cargo-installnrFCmC/release/deps/libpest_generator-16ba334e3366017b.rlib --cap-lints allow`
   Compiling comrak v0.5.0                                                                                                                             
     Running `rustc --crate-name comrak /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/comrak-0.5.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="clap"' --cfg 'feature="default"' -C metadata=0dc11868b60c7c8d -C extra-filename=-0dc11868b60c7c8d --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern clap=/tmp/cargo-installnrFCmC/release/deps/libclap-1677959eed09ed9b.rlib --extern entities=/tmp/cargo-installnrFCmC/release/deps/libentities-b41079d2b7f63e1a.rlib --extern lazy_static=/tmp/cargo-installnrFCmC/release/deps/liblazy_static-2af91ade475ddbea.rlib --extern pest=/tmp/cargo-installnrFCmC/release/deps/libpest-1af1081016174dd9.rlib --extern pest_derive=/tmp/cargo-installnrFCmC/release/deps/libpest_derive-9d1e413f5b3f6f9e.so --extern regex=/tmp/cargo-installnrFCmC/release/deps/libregex-c8d2be83cc7ee0e8.rlib --extern twoway=/tmp/cargo-installnrFCmC/release/deps/libtwoway-445ae107fc8ff1ce.rlib --extern typed_arena=/tmp/cargo-installnrFCmC/release/deps/libtyped_arena-79fb06894b14b115.rlib --extern unicode_categories=/tmp/cargo-installnrFCmC/release/deps/libunicode_categories-769eb0b437b32a41.rlib --cap-lints allow`
error[E0658]: `Self` struct constructors are unstable (see issue #51994)                                                                               
  --> /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/comrak-0.5.0/src/html.rs:73:9                                                      
   |                                                                                                                                                   
73 |         Self(HashSet::new())                                                                                                                      
   |         ^^^^                                                                                                                                      
                                                                                                                                                       
error: aborting due to previous error                                                                                                                  
                                                                                                                                                       
For more information about this error, try `rustc --explain E0658`.                                                                                    
error: failed to compile `comrak v0.5.0`, intermediate artifacts can be found at `/tmp/cargo-installnrFCmC`                                            

Caused by:
  Could not compile `comrak`.

Caused by:
  process didn't exit successfully: `rustc --crate-name comrak /home/chronos/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/comrak-0.5.0/src/lib.rs --color always --crate-type lib --emit=dep-info,link -C opt-level=3 --cfg 'feature="clap"' --cfg 'feature="default"' -C metadata=0dc11868b60c7c8d -C extra-filename=-0dc11868b60c7c8d --out-dir /tmp/cargo-installnrFCmC/release/deps -L dependency=/tmp/cargo-installnrFCmC/release/deps --extern clap=/tmp/cargo-installnrFCmC/release/deps/libclap-1677959eed09ed9b.rlib --extern entities=/tmp/cargo-installnrFCmC/release/deps/libentities-b41079d2b7f63e1a.rlib --extern lazy_static=/tmp/cargo-installnrFCmC/release/deps/liblazy_static-2af91ade475ddbea.rlib --extern pest=/tmp/cargo-installnrFCmC/release/deps/libpest-1af1081016174dd9.rlib --extern pest_derive=/tmp/cargo-installnrFCmC/release/deps/libpest_derive-9d1e413f5b3f6f9e.so --extern regex=/tmp/cargo-installnrFCmC/release/deps/libregex-c8d2be83cc7ee0e8.rlib --extern twoway=/tmp/cargo-installnrFCmC/release/deps/libtwoway-445ae107fc8ff1ce.rlib --extern typed_arena=/tmp/cargo-installnrFCmC/release/deps/libtyped_arena-79fb06894b14b115.rlib --extern unicode_categories=/tmp/cargo-installnrFCmC/release/deps/libunicode_categories-769eb0b437b32a41.rlib --cap-lints allow` (exit code: 1)

I am using the following versions on Alpine Linux edge:

localhost:~$ cargo --version
cargo 1.31.0
localhost:~$ rustc --version
rustc 1.31.1

[kivikakk]

In general I only guarantee that a given comrak release will build against the stable Rust release at the time, but I think it's time to give some better guarantees. I'll see how far back I can easily support and make a new release with that adjusted -- I'll let you know when it's done, but it'll definitely cover 1.31.

[kivikakk]

Comrak 0.5.1 has been released! This should build on everything back to 1.27. Here's a build with your tool versions:

$ rustup override set 1.31.1
info: syncing channel updates for '1.31.1-x86_64-apple-darwin'
info: latest update on 2018-12-20, rust version 1.31.1 (b6c32da9b 2018-12-18)
info: downloading component 'rustc'
 62.6 MiB /  62.6 MiB (100 %)   4.2 MiB/s ETA:   0 s
info: downloading component 'rust-std'
 49.0 MiB /  49.0 MiB (100 %)   2.4 MiB/s ETA:   0 s
info: downloading component 'cargo'
info: downloading component 'rust-docs'
  8.5 MiB /   8.5 MiB (100 %)   1.8 MiB/s ETA:   0 s
info: installing component 'rustc'
info: installing component 'rust-std'
info: installing component 'cargo'
info: installing component 'rust-docs'
info: override toolchain for '/Users/kivikakk/kivikakk/comrak' set to '1.31.1-x86_64-apple-darwin'

  1.31.1-x86_64-apple-darwin installed - rustc 1.31.1 (b6c32da9b 2018-12-18)

$ cargo --version
cargo 1.31.0 (339d9f9c8 2018-11-16)
$ rustc --version
rustc 1.31.1 (b6c32da9b 2018-12-18)
$ cargo build
   Compiling proc-macro2 v0.4.20
   Compiling unicode-xid v0.1.0
   Compiling ucd-trie v0.1.1
   Compiling maplit v1.0.1
   Compiling void v1.0.2
   Compiling libc v0.2.42
   Compiling ucd-util v0.1.1
   Compiling unicode-width v0.1.5
   Compiling regex v1.0.1
   Compiling lazy_static v1.0.1
   Compiling ansi_term v0.11.0
   Compiling strsim v0.7.0
   Compiling vec_map v0.8.1
   Compiling bitflags v1.0.3
   Compiling utf8-ranges v1.0.0
   Compiling entities v1.0.1
   Compiling unicode_categories v0.1.1
   Compiling typed-arena v1.4.1
   Compiling unreachable v1.0.0
   Compiling textwrap v0.10.0
   Compiling regex-syntax v0.6.1
   Compiling pest v2.0.2
   Compiling memchr v2.0.1
   Compiling atty v0.2.10
   Compiling thread_local v0.3.5
   Compiling aho-corasick v0.6.5
   Compiling twoway v0.1.8
   Compiling clap v2.32.0
   Compiling quote v0.6.9
   Compiling pest_meta v2.0.3
   Compiling syn v0.14.9
   Compiling pest_generator v2.0.0
   Compiling pest_derive v2.0.1
   Compiling comrak v0.5.1 (/Users/kivikakk/kivikakk/comrak)
    Finished dev [unoptimized + debuginfo] target(s) in 38.58s
$

[maxwell-k]

Fantastic, thank you @kivikakk, I can confirm that 0.5.1 is working great!

[kivikakk]

Awesome, glad to hear it!