Large locals can cause OOMs during the ConstProp pass

[wesleywiser]

The following ICEs on beta and nightly:

fn main() {
    [0; 4 * 1024 * 1024 * 1024 * 1024];
}

(playground)

gdb backtrace

#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1  0x00007ffff3de055d in __GI_abort () at abort.c:79
#2  0x00007ffff403f9e7 in std::sys::unix::abort_internal () at src/libstd/sys/unix/mod.rs:155
#3  0x00007ffff402612d in rust_oom (layout=...) at src/libstd/alloc.rs:217
#4  0x00007ffff405de67 in alloc::alloc::handle_alloc_error (layout=...) at src/liballoc/alloc.rs:247
#5  0x00007ffff58a9f56 in alloc::raw_vec::RawVec<T,A>::allocate_in (capacity=17592186044416, zeroed=255, a=...) at /home/wesley/code/rust/rust/src/liballoc/raw_vec.rs:102
#6  alloc::raw_vec::RawVec<T>::with_capacity_zeroed (capacity=17592186044416) at /home/wesley/code/rust/rust/src/liballoc/raw_vec.rs:173
#7  <u8 as alloc::vec::SpecFromElem>::from_elem (elem=0, n=17592186044416) at /home/wesley/code/rust/rust/src/liballoc/vec.rs:1715
#8  alloc::vec::from_elem (elem=0, n=17592186044416) at /home/wesley/code/rust/rust/src/liballoc/vec.rs:1694
#9  rustc::mir::interpret::allocation::Allocation<Tag>::undef (size=..., align=...) at <::alloc::macros::vec macros>:1
#10 0x00007ffff5247c50 in rustc_mir::interpret::memory::Memory<M>::allocate (self=0x7ffff3b55068, size=..., align=..., kind=rustc_mir::interpret::memory::MemoryKind::Stack)
    at src/librustc_mir/interpret/memory.rs:172
#11 0x00007ffff528be1e in rustc_mir::interpret::place::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::force_allocation_maybe_sized (self=<optimized out>, place=..., meta=...)
    at src/librustc_mir/interpret/place.rs:994
#12 0x00007ffff52af57f in rustc_mir::interpret::place::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::force_allocation (self=0x7ffff3b55040, place=...) at src/librustc_mir/interpret/place.rs:1023
#13 rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_rvalue_into_place (self=0x7ffff3b55040, rvalue=<optimized out>, place=<optimized out>)
    at src/librustc_mir/interpret/step.rs:210
#14 0x00007ffff54ab6f4 in rustc_mir::transform::const_prop::ConstPropagator::const_prop::{{closure}} (this=0x7ffff3b55040) at src/librustc_mir/transform/const_prop.rs:578
#15 rustc_mir::transform::const_prop::ConstPropagator::use_ecx (self=0x7ffff3b55040, source_info=..., f=...) at src/librustc_mir/transform/const_prop.rs:394
--Type <RET> for more, q to quit, c to continue without paging--c
#16 0x00007ffff52ede17 in rustc_mir::transform::const_prop::ConstPropagator::const_prop (self=0x7ffff3b55040, rvalue=<optimized out>, place_layout=..., source_info=..., place=<optimized out>) at src/librustc_mir/transform/const_prop.rs:576
#17 <rustc_mir::transform::const_prop::ConstPropagator as rustc::mir::visit::MutVisitor>::visit_statement (self=0x7ffff3b55040, statement=<optimized out>, location=...) at src/librustc_mir/transform/const_prop.rs:746
#18 0x00007ffff54a7493 in rustc::mir::visit::MutVisitor::super_basic_block_data (self=0x7ffff3b55040, block=..., data=<optimized out>) at /home/wesley/code/rust/rust/src/librustc/mir/visit.rs:297
#19 rustc::mir::visit::MutVisitor::visit_basic_block_data (self=0x7ffff3b55040, block=..., data=<optimized out>) at /home/wesley/code/rust/rust/src/librustc/mir/visit.rs:81
#20 rustc::mir::visit::MutVisitor::super_body (self=<optimized out>, body=<optimized out>) at /home/wesley/code/rust/rust/src/librustc/mir/visit.rs:255
#21 rustc::mir::visit::MutVisitor::visit_body (self=0x7ffff3b55040, body=0x7ffff3b55b68) at /home/wesley/code/rust/rust/src/librustc/mir/visit.rs:75
#22 0x00007ffff52ebca3 in <rustc_mir::transform::const_prop::ConstProp as rustc_mir::transform::MirPass>::run_pass (self=<optimized out>, tcx=..., source=..., body=<optimized out>) at src/librustc_mir/transform/const_prop.rs:108
#23 0x00007ffff53289de in rustc_mir::transform::run_passes::{{closure}} (pass=...) at src/librustc_mir/transform/mod.rs:175
#24 rustc_mir::transform::run_passes (tcx=..., body=0x7ffff3b55b68, instance=..., promoted=..., mir_phase=rustc::mir::MirPhase::Optimized, passes=...) at src/librustc_mir/transform/mod.rs:182
#25 0x00007ffff5329a6b in rustc_mir::transform::run_optimization_passes (tcx=..., body=0x7ffff3b55b68, def_id=..., promoted=...) at src/librustc_mir/transform/mod.rs:231
#26 0x00007ffff5329e4b in rustc_mir::transform::optimized_mir (tcx=..., def_id=...) at src/librustc_mir/transform/mod.rs:301
#27 0x00007ffff6bad49b in rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::optimized_mir>::compute (tcx=..., key=...) at src/librustc/ty/query/plumbing.rs:944
#28 0x00007ffff6773a18 in rustc::dep_graph::graph::DepGraph::with_task_impl (self=<optimized out>, key=..., cx=..., arg=..., no_tcx=false, task=0x7ffff6bad480 <rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::optimized_mir>::compute>, create_task=0x7ffff6743c20 <core::ops::function::FnOnce::call_once>, finish_task_and_alloc_depnode=0x7ffff6743cf0 <core::ops::function::FnOnce::call_once>, hash_result=<optimized out>) at src/librustc/dep_graph/graph.rs:322
#29 0x00007ffff6a11d26 in rustc::dep_graph::graph::DepGraph::with_task (self=0x2, cx=..., arg=..., task=0x7ffff3b53c10, key=..., hash_result=<optimized out>) at src/librustc/dep_graph/graph.rs:198
#30 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}::{{closure}} (tcx=...) at src/librustc/ty/query/plumbing.rs:526
#31 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}} () at src/librustc/ty/query/plumbing.rs:258
#32 rustc::ty::context::tls::enter_context::{{closure}} () at src/librustc/ty/context.rs:1861
#33 rustc::ty::context::tls::set_tlv (value=<optimized out>, f=...) at src/librustc/ty/context.rs:1794
#34 rustc::ty::context::tls::enter_context (context=<optimized out>, f=...) at src/librustc/ty/context.rs:1860
#35 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}} (current_icx=<optimized out>) at src/librustc/ty/query/plumbing.rs:257
#36 rustc::ty::context::tls::with_related_context::{{closure}} (context=<optimized out>) at src/librustc/ty/context.rs:1967
#37 rustc::ty::context::tls::with_context::{{closure}} (opt_context=...) at src/librustc/ty/context.rs:1950
#38 rustc::ty::context::tls::with_context_opt (f=...) at src/librustc/ty/context.rs:1939
#39 rustc::ty::context::tls::with_context (f=...) at src/librustc/ty/context.rs:1950
#40 rustc::ty::context::tls::with_related_context (f=..., tcx=...) at src/librustc/ty/context.rs:1963
#41 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query (job=..., diagnostics=..., compute=..., self=...) at src/librustc/ty/query/plumbing.rs:246
#42 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}} (diagnostics=...) at src/librustc/ty/query/plumbing.rs:518
#43 rustc::ty::query::plumbing::with_diagnostics (f=...) at src/librustc/ty/query/plumbing.rs:191
#44 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job (self=..., key=..., job=..., dep_node=...) at src/librustc/ty/query/plumbing.rs:517
#45 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query (self=..., span=..., key=...) at src/librustc/ty/query/plumbing.rs:354
#46 0x00007ffff51e2373 in rustc_mir::monomorphize::collector::collect_neighbours (tcx=..., instance=..., output=0x7ffff3b56838) at src/librustc_mir/monomorphize/collector.rs:1254
#47 rustc_mir::monomorphize::collector::collect_items_rec (tcx=..., starting_point=..., visited=0x7ffff3b56b10, recursion_depths=0x7ffff3b568b8, inlining_map=0x7ffff3b56a50) at src/librustc_mir/monomorphize/collector.rs:403
#48 0x00007ffff5265bfb in rustc_mir::monomorphize::collector::collect_crate_mono_items::{{closure}}::{{closure}} (root=...) at src/librustc_mir/monomorphize/collector.rs:311
#49 core::iter::traits::iterator::Iterator::for_each::call::{{closure}} (item=...) at /home/wesley/code/rust/rust/src/libcore/iter/traits/iterator.rs:628
#50 core::iter::traits::iterator::Iterator::fold::ok::{{closure}} (acc=<optimized out>, x=...) at /home/wesley/code/rust/rust/src/libcore/iter/traits/iterator.rs:1828
#51 core::iter::traits::iterator::Iterator::try_fold (self=0x7ffff3b56898, f=..., init=<optimized out>) at /home/wesley/code/rust/rust/src/libcore/iter/traits/iterator.rs:1709
#52 core::iter::traits::iterator::Iterator::fold (self=..., f=..., init=<optimized out>) at /home/wesley/code/rust/rust/src/libcore/iter/traits/iterator.rs:1831
#53 core::iter::traits::iterator::Iterator::for_each (self=..., f=...) at /home/wesley/code/rust/rust/src/libcore/iter/traits/iterator.rs:631
#54 rustc_mir::monomorphize::collector::collect_crate_mono_items::{{closure}} () at src/librustc_mir/monomorphize/collector.rs:309
#55 0x00007ffff5265697 in rustc::util::common::time_ext (do_it=<optimized out>, what=..., f=...) at /home/wesley/code/rust/rust/src/librustc/util/common.rs:55
#56 rustc::util::common::time (sess=<optimized out>, what=..., f=...) at /home/wesley/code/rust/rust/src/librustc/util/common.rs:49
#57 0x00007ffff51e14e9 in rustc_mir::monomorphize::collector::collect_crate_mono_items (tcx=..., mode=<optimized out>) at src/librustc_mir/monomorphize/collector.rs:308
#58 0x00007ffff52657f6 in rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items::{{closure}} () at src/librustc_mir/monomorphize/partitioning.rs:889
#59 rustc::util::common::time_ext (do_it=false, what=..., f=...) at /home/wesley/code/rust/rust/src/librustc/util/common.rs:55
#60 rustc::util::common::time (sess=<optimized out>, what=..., f=...) at /home/wesley/code/rust/rust/src/librustc/util/common.rs:49
#61 0x00007ffff58d52d0 in rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items (tcx=..., cnum=...) at src/librustc_mir/monomorphize/partitioning.rs:888
#62 0x00007fffe85e9de0 in rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::collect_and_partition_mono_items>::compute::{{closure}} () at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:952
#63 rustc::ty::query::__query_compute::collect_and_partition_mono_items (f=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:903
#64 0x00007fffe86a2919 in rustc::dep_graph::graph::DepGraph::with_task_impl (self=<optimized out>, key=<error reading variable: Cannot access memory at address 0x0>, cx=..., arg=..., no_tcx=false, task=0x7fffe86df730 <rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::collect_and_partition_mono_items>::compute>, create_task=0x7fffe869c890 <core::ops::function::FnOnce::call_once>, finish_task_and_alloc_depnode=0x7fffe869c8a0 <core::ops::function::FnOnce::call_once>, hash_result=<optimized out>) at /home/wesley/code/rust/rust/src/librustc/dep_graph/graph.rs:322
#65 0x00007fffe871672e in rustc::dep_graph::graph::DepGraph::with_eval_always_task (self=0x7ffff3b53c10, cx=..., arg=..., task=0x7ffff3b53c10, key=..., hash_result=<optimized out>) at /home/wesley/code/rust/rust/src/librustc/dep_graph/graph.rs:374
#66 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}::{{closure}} (tcx=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:520
#67 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}} () at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:258
#68 rustc::ty::context::tls::enter_context::{{closure}} () at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1861
#69 rustc::ty::context::tls::set_tlv (value=<optimized out>, f=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1794
#70 rustc::ty::context::tls::enter_context (context=<optimized out>, f=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1860
#71 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}} (current_icx=<optimized out>) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:257
#72 rustc::ty::context::tls::with_related_context::{{closure}} (context=<optimized out>) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1967
#73 rustc::ty::context::tls::with_context::{{closure}} (opt_context=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1950
#74 rustc::ty::context::tls::with_context_opt (f=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1939
#75 rustc::ty::context::tls::with_context (f=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1950
#76 rustc::ty::context::tls::with_related_context (f=..., tcx=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1963
#77 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query (job=..., diagnostics=..., compute=..., self=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:246
#78 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}} (diagnostics=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:518
#79 rustc::ty::query::plumbing::with_diagnostics (f=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:191
#80 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job (self=..., key=..., job=..., dep_node=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:517
#81 rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query (self=..., span=..., key=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:354
#82 0x00007fffe882ec21 in rustc::ty::query::TyCtxtAt::collect_and_partition_mono_items (self=..., key=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:1029
#83 rustc::ty::query::<impl rustc::ty::context::TyCtxt>::collect_and_partition_mono_items (self=..., key=...) at /home/wesley/code/rust/rust/src/librustc/ty/query/plumbing.rs:1021
#84 rustc_codegen_ssa::base::codegen_crate (backend=..., tcx=..., metadata=..., need_metadata_module=false) at /home/wesley/code/rust/rust/src/librustc_codegen_ssa/base.rs:519
#85 0x00007fffe869ad5e in <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_utils::codegen_backend::CodegenBackend>::codegen_crate (self=<optimized out>, tcx=..., metadata=..., need_metadata_module=false) at src/librustc_codegen_llvm/lib.rs:281
#86 0x00007ffff454805e in rustc_interface::passes::start_codegen::{{closure}} () at src/librustc_interface/passes.rs:1038
#87 0x00007ffff4542cbe in rustc::util::common::time_ext (do_it=<optimized out>, what=..., f=...) at /home/wesley/code/rust/rust/src/librustc/util/common.rs:55
#88 rustc::util::common::time (sess=<optimized out>, what=..., f=...) at /home/wesley/code/rust/rust/src/librustc/util/common.rs:49
#89 0x00007ffff46b9015 in rustc_interface::passes::start_codegen (codegen_backend=..., tcx=..., outputs=0x7ffff3b5f7c8) at src/librustc_interface/passes.rs:1036
#90 0x00007ffff4552ca0 in rustc_interface::queries::<impl rustc_interface::interface::Compiler>::ongoing_codegen::{{closure}}::{{closure}} (tcx=...) at src/librustc_interface/queries.rs:254
#91 rustc_interface::passes::BoxedGlobalCtxt::enter::{{closure}}::{{closure}} (tcx=...) at src/librustc_interface/passes.rs:773
#92 rustc::ty::context::tls::enter_global::{{closure}} () at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1893
#93 rustc::ty::context::tls::enter_context::{{closure}} () at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1861
#94 rustc::ty::context::tls::set_tlv (value=140737282147056, f=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1794
#95 rustc::ty::context::tls::enter_context (context=0x7ffff3b582f0, f=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1860
#96 rustc::ty::context::tls::enter_global (gcx=0x7fffec21dca8, f=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1892
#97 0x00007ffff4657736 in rustc_interface::passes::BoxedGlobalCtxt::enter::{{closure}} (gcx=0x0) at src/librustc_interface/passes.rs:773
#98 rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}} (args=...) at <::rustc_data_structures::box_region::declare_box_region_type macros>:21
#99 0x00007ffff45c852b in rustc_interface::passes::create_global_ctxt::{{closure}} () at src/librustc_interface/passes.rs:836
#100 0x00007ffff46568ea in alloc::boxed::<impl core::ops::generator::Generator for core::pin::Pin<alloc::boxed::Box<G>>>::resume (self=...) at /home/wesley/code/rust/rust/src/liballoc/boxed.rs:1093
#101 rustc_data_structures::box_region::PinnedGenerator<I,A,R>::access (self=<optimized out>, closure=...) at /home/wesley/code/rust/rust/src/librustc_data_structures/box_region.rs:52
#102 rustc_interface::passes::BoxedGlobalCtxt::access (self=<optimized out>, f=...) at <::rustc_data_structures::box_region::declare_box_region_type macros>:24
#103 rustc_interface::passes::BoxedGlobalCtxt::enter (self=0x7ffff3b5f850, f=...) at src/librustc_interface/passes.rs:773
#104 0x00007ffff46501a2 in rustc_interface::queries::<impl rustc_interface::interface::Compiler>::ongoing_codegen::{{closure}} () at src/librustc_interface/queries.rs:248
#105 rustc_interface::queries::Query<T>::compute (self=0x7ffff3b5f860, f=...) at src/librustc_interface/queries.rs:32
#106 0x00007ffff45cb9b4 in rustc_interface::queries::<impl rustc_interface::interface::Compiler>::ongoing_codegen (self=<optimized out>) at src/librustc_interface/queries.rs:246
#107 0x00007ffff44fbebe in rustc_driver::run_compiler::{{closure}} (compiler=0x2) at src/librustc_driver/lib.rs:390
#108 rustc_interface::interface::run_compiler_in_existing_thread_pool (config=..., f=...) at /home/wesley/code/rust/rust/src/librustc_interface/interface.rs:166
#109 0x00007ffff44f12c0 in rustc_interface::interface::run_compiler::{{closure}} () at /home/wesley/code/rust/rust/src/librustc_interface/interface.rs:179
#110 rustc_interface::util::spawn_thread_pool::{{closure}}::{{closure}}::{{closure}}::{{closure}} () at /home/wesley/code/rust/rust/src/librustc_interface/util.rs:189
#111 rustc::ty::context::tls::with_thread_locals::{{closure}}::{{closure}} (current=0x7ffff3b666a8) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1849
#112 std::thread::local::LocalKey<T>::try_with (f=..., self=<optimized out>) at /home/wesley/code/rust/rust/src/libstd/thread/local.rs:262
#113 std::thread::local::LocalKey<T>::with (self=<optimized out>, f=...) at /home/wesley/code/rust/rust/src/libstd/thread/local.rs:239
#114 rustc::ty::context::tls::with_thread_locals::{{closure}} (span_dbg=0x7ffff3b666d0) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1841
#115 std::thread::local::LocalKey<T>::try_with (self=<optimized out>, f=...) at /home/wesley/code/rust/rust/src/libstd/thread/local.rs:262
#116 std::thread::local::LocalKey<T>::with (self=<optimized out>, f=...) at /home/wesley/code/rust/rust/src/libstd/thread/local.rs:239
#117 0x00007ffff4499f05 in rustc::ty::context::tls::with_thread_locals (f=...) at /home/wesley/code/rust/rust/src/librustc/ty/context.rs:1833
#118 rustc_interface::util::spawn_thread_pool::{{closure}}::{{closure}}::{{closure}} () at /home/wesley/code/rust/rust/src/librustc_interface/util.rs:189
#119 scoped_tls::ScopedKey<T>::set (self=0x7ffff7f755b8 <rustc::ty::context::tls::GCX_PTR>, t=0x7ffff3b61d60, f=...) at /home/wesley/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/scoped-tls-1.0.0/src/lib.rs:137
#120 rustc_interface::util::spawn_thread_pool::{{closure}}::{{closure}} () at /home/wesley/code/rust/rust/src/librustc_interface/util.rs:185
#121 scoped_tls::ScopedKey<T>::set (self=<optimized out>, t=<optimized out>, f=...) at /home/wesley/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/scoped-tls-1.0.0/src/lib.rs:137
#122 syntax::with_globals::{{closure}} () at /home/wesley/code/rust/rust/src/libsyntax/lib.rs:62
#123 scoped_tls::ScopedKey<T>::set (self=<optimized out>, t=<optimized out>, f=...) at /home/wesley/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/scoped-tls-1.0.0/src/lib.rs:137
#124 0x00007ffff44c1fe2 in syntax::with_globals (edition=<optimized out>, f=...) at /home/wesley/code/rust/rust/src/libsyntax/lib.rs:61
#125 0x00007ffff4466586 in rustc_interface::util::spawn_thread_pool::{{closure}} () at /home/wesley/code/rust/rust/src/librustc_interface/util.rs:184
#126 rustc_interface::util::scoped_thread::{{closure}} () at /home/wesley/code/rust/rust/src/librustc_interface/util.rs:161
#127 std::sys_common::backtrace::__rust_begin_short_backtrace (f=...) at /home/wesley/code/rust/rust/src/libstd/sys_common/backtrace.rs:129
#128 0x00007ffff4456e99 in std::thread::Builder::spawn_unchecked::{{closure}}::{{closure}} () at /home/wesley/code/rust/rust/src/libstd/thread/mod.rs:469
#129 <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once (self=..., _args=<optimized out>) at /home/wesley/code/rust/rust/src/libstd/panic.rs:317
#130 std::panicking::try::do_call (data=<optimized out>) at /home/wesley/code/rust/rust/src/libstd/panicking.rs:287
#131 0x00007ffff404bee4 in __rust_maybe_catch_panic (f=0x0, data=0x2 <error: Cannot access memory at address 0x2>, data_ptr=0x7ffff3b65960, vtable_ptr=0x7ffff3b65968) at src/libpanic_unwind/lib.rs:79
#132 0x00007ffff4456aea in std::panicking::try (f=...) at /home/wesley/code/rust/rust/src/libstd/panicking.rs:265
#133 0x00007ffff445360e in std::panic::catch_unwind (f=<error reading variable: access outside bounds of object referenced via synthetic pointer>) at /home/wesley/code/rust/rust/src/libstd/panic.rs:396
#134 std::thread::Builder::spawn_unchecked::{{closure}} () at /home/wesley/code/rust/rust/src/libstd/thread/mod.rs:468
#135 core::ops::function::FnOnce::call_once{{vtable-shim}} () at /home/wesley/code/rust/rust/src/libcore/ops/function.rs:227
#136 0x00007ffff40433ef in <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once (self=..., args=<optimized out>) at /home/wesley/code/rust/rust/src/liballoc/boxed.rs:942
#137 0x00007ffff3fffa70 in <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once (self=0x555555559d10, args=<optimized out>) at /home/wesley/code/rust/rust/src/liballoc/boxed.rs:942
#138 std::sys_common::thread::start_thread (main=0x555555559d10 "\020\306UUUU") at src/libstd/sys_common/thread.rs:13
#139 0x00007ffff4005336 in std::sys::unix::thread::Thread::new::thread_start (main=0x2) at src/libstd/sys/unix/thread.rs:79
#140 0x00007ffff3cd0f2a in start_thread (arg=<optimized out>) at pthread_create.c:479
#141 0x00007ffff3eba4af in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

[pnkfelix]

triage: P-high.