Can't generate C-binding for Mac OS

[ababo]

When doing make include/accesskit.h I get:

rustup run nightly cbindgen | clang-format '--assume-filename=*.c' > include/accesskit.h
ERROR: Parsing crate `accesskit_c`: couldn't run `cargo rustc -Zunpretty=expanded`: Compile("   Compiling objc-sys v0.2.0-beta.2\n   Compiling paste v1.0.12\n    Checking accesskit v0.11.0 (/Users/ababo/Desktop/accesskit/common)\n    Checking once_cell v1.17.1\n     Running `rustc --crate-name build_script_build --edition=2021 /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/objc-sys-0.2.0-beta.2/build.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type bin --emit=dep-info,link -C embed-bitcode=no -C split-debuginfo=unpacked --cfg 'feature=\"alloc\"' --cfg 'feature=\"apple\"' --cfg 'feature=\"std\"' -C metadata=220f63b3ce9ff133 -C extra-filename=-220f63b3ce9ff133 --out-dir /Users/ababo/Desktop/accesskit/target/debug/build/objc-sys-220f63b3ce9ff133 -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --cap-lints allow`\n     Running `rustc --crate-name build_script_build --edition=2018 /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/paste-1.0.12/build.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type bin --emit=dep-info,link -C embed-bitcode=no -C split-debuginfo=unpacked -C metadata=a16a7e33d8fe27a8 -C extra-filename=-a16a7e33d8fe27a8 --out-dir /Users/ababo/Desktop/accesskit/target/debug/build/paste-a16a7e33d8fe27a8 -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --cap-lints allow`\n     Running `rustc --crate-name once_cell --edition=2021 /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/once_cell-1.17.1/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C split-debuginfo=unpacked -C debuginfo=2 --cfg 'feature=\"alloc\"' --cfg 'feature=\"default\"' --cfg 'feature=\"race\"' --cfg 'feature=\"std\"' -C metadata=2a7f93e778555b50 -C extra-filename=-2a7f93e778555b50 --out-dir /Users/ababo/Desktop/accesskit/target/debug/deps -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --cap-lints allow`\n     Running `rustc --crate-name accesskit --edition=2021 common/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C split-debuginfo=unpacked -C debuginfo=2 -C metadata=4e1d10932258b155 -C extra-filename=-4e1d10932258b155 --out-dir /Users/ababo/Desktop/accesskit/target/debug/deps -C incremental=/Users/ababo/Desktop/accesskit/target/debug/incremental -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps`\n     Running `/Users/ababo/Desktop/accesskit/target/debug/build/paste-a16a7e33d8fe27a8/build-script-build`\n     Running `/Users/ababo/Desktop/accesskit/target/debug/build/objc-sys-220f63b3ce9ff133/build-script-build`\n    Checking accesskit_consumer v0.15.0 (/Users/ababo/Desktop/accesskit/consumer)\n     Running `rustc --crate-name accesskit_consumer --edition=2021 consumer/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C split-debuginfo=unpacked -C debuginfo=2 -C metadata=819d4ea332376bc3 -C extra-filename=-819d4ea332376bc3 --out-dir /Users/ababo/Desktop/accesskit/target/debug/deps -C incremental=/Users/ababo/Desktop/accesskit/target/debug/incremental -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --extern accesskit=/Users/ababo/Desktop/accesskit/target/debug/deps/libaccesskit-4e1d10932258b155.rmeta`\n     Running `rustc --crate-name paste --edition=2018 /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/paste-1.0.12/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type proc-macro --emit=dep-info,link -C prefer-dynamic -C embed-bitcode=no -C split-debuginfo=unpacked -C metadata=f9c6ee9186bc447f -C extra-filename=-f9c6ee9186bc447f --out-dir /Users/ababo/Desktop/accesskit/target/debug/deps -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --extern proc_macro --cap-lints allow`\n     Running `rustc --crate-name objc_sys --edition=2021 /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/objc-sys-0.2.0-beta.2/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C split-debuginfo=unpacked -C debuginfo=2 --cfg 'feature=\"alloc\"' --cfg 'feature=\"apple\"' --cfg 'feature=\"std\"' -C metadata=dd06ec88ad260d98 -C extra-filename=-dd06ec88ad260d98 --out-dir /Users/ababo/Desktop/accesskit/target/debug/deps -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --cap-lints allow -l dylib=objc --cfg apple --cfg apple_new`\n    Checking objc2-encode v2.0.0-pre.2\n     Running `rustc --crate-name objc2_encode --edition=2021 /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/objc2-encode-2.0.0-pre.2/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C split-debuginfo=unpacked -C debuginfo=2 --cfg 'feature=\"alloc\"' --cfg 'feature=\"apple\"' --cfg 'feature=\"std\"' -C metadata=89826d8f72b45eea -C extra-filename=-89826d8f72b45eea --out-dir /Users/ababo/Desktop/accesskit/target/debug/deps -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --extern objc_sys=/Users/ababo/Desktop/accesskit/target/debug/deps/libobjc_sys-dd06ec88ad260d98.rmeta --cap-lints allow`\n    Checking objc2 v0.3.0-beta.3.patch-leaks.2\n     Running `rustc --crate-name objc2 --edition=2021 /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/objc2-0.3.0-beta.3.patch-leaks.2/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C split-debuginfo=unpacked -C debuginfo=2 --cfg 'feature=\"alloc\"' --cfg 'feature=\"apple\"' --cfg 'feature=\"default\"' --cfg 'feature=\"foundation\"' --cfg 'feature=\"std\"' -C metadata=22d343e4bc921c49 -C extra-filename=-22d343e4bc921c49 --out-dir /Users/ababo/Desktop/accesskit/target/debug/deps -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --extern objc_sys=/Users/ababo/Desktop/accesskit/target/debug/deps/libobjc_sys-dd06ec88ad260d98.rmeta --extern objc2_encode=/Users/ababo/Desktop/accesskit/target/debug/deps/libobjc2_encode-89826d8f72b45eea.rmeta --cap-lints allow`\nerror[E0277]: `<<I as IvarType>::Type as InnerIvarType>::Output` is not an iterator\n   --> /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/objc2-0.3.0-beta.3.patch-leaks.2/src/declare/ivar_forwarding_impls.rs:165:5\n    |\n165 |     fn nth(&mut self, n: usize) -> Option<<<Self as Deref>::Target as Iterator>::Item> {\n    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `<<I as IvarType>::Type as InnerIvarType>::Output` is not an iterator\n    |\n    = help: the trait `Iterator` is not implemented for `<<I as IvarType>::Type as InnerIvarType>::Output`\nnote: required for `ivar::Ivar<I>` to implement `Iterator`\n   --> /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/objc2-0.3.0-beta.3.patch-leaks.2/src/declare/ivar_forwarding_impls.rs:154:19\n    |\n154 | impl<I: IvarType> Iterator for Ivar<I>\n    |                   ^^^^^^^^     ^^^^^^^\n155 | where\n156 |     <Self as Deref>::Target: Iterator,\n    |                              -------- unsatisfied trait bound introduced here\nhelp: consider further restricting the associated type\n    |\n165 |     fn nth(&mut self, n: usize) -> Option<<<Self as Deref>::Target as Iterator>::Item> where <<I as IvarType>::Type as InnerIvarType>::Output: Iterator {\n    |                                                                                        ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++\n\nerror[E0277]: `<<I as IvarType>::Type as InnerIvarType>::Output` is not an iterator\n   --> /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/objc2-0.3.0-beta.3.patch-leaks.2/src/declare/ivar_forwarding_impls.rs:165:5\n    |\n165 |     fn nth(&mut self, n: usize) -> Option<<<Self as Deref>::Target as Iterator>::Item> {\n    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `<<I as IvarType>::Type as InnerIvarType>::Output` is not an iterator\n    |\n    = help: the trait `Iterator` is not implemented for `<<I as IvarType>::Type as InnerIvarType>::Output`\nhelp: consider further restricting the associated type\n    |\n165 |     fn nth(&mut self, n: usize) -> Option<<<Self as Deref>::Target as Iterator>::Item> where <<I as IvarType>::Type as InnerIvarType>::Output: Iterator {\n    |                                                                                        ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++\n\nFor more information about this error, try `rustc --explain E0277`.\nerror: could not compile `objc2` (lib) due to 2 previous errors\n\nCaused by:\n  process didn't exit successfully: `rustc --crate-name objc2 --edition=2021 /Users/ababo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/objc2-0.3.0-beta.3.patch-leaks.2/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C split-debuginfo=unpacked -C debuginfo=2 --cfg 'feature=\"alloc\"' --cfg 'feature=\"apple\"' --cfg 'feature=\"default\"' --cfg 'feature=\"foundation\"' --cfg 'feature=\"std\"' -C metadata=22d343e4bc921c49 -C extra-filename=-22d343e4bc921c49 --out-dir /Users/ababo/Desktop/accesskit/target/debug/deps -L dependency=/Users/ababo/Desktop/accesskit/target/debug/deps --extern objc_sys=/Users/ababo/Desktop/accesskit/target/debug/deps/libobjc_sys-dd06ec88ad260d98.rmeta --extern objc2_encode=/Users/ababo/Desktop/accesskit/target/debug/deps/libobjc2_encode-89826d8f72b45eea.rmeta --cap-lints allow` (exit status: 1)\n")
ERROR: Couldn't generate bindings for /Users/ababo/Desktop/accesskit/bindings/c.

[mwcampbell]

Looks like we can't generate the header file on macOS due to errors when compiling objc2 with the nightly compiler. Please use our pre-built header file and libraries instead; here's the current accesskit_c release.

[madsmtm]

I think this is fixed by now, see madsmtm/objc2#432

[DataTriny]

We got no feedback from the author for a few months now, closing per the comment above.

Please re-open this if the issue occurs again.