"Resource temporarily unavailable" panic in rustc_interface::util::spawn_thread_pool

[icy-ux]

Code

It's unknown which part of the code triggered this bug, it seems to happen quite early while compiling. The bug seems to be related to system load, the code compiled fine after some other processes running on the system were killed.

Meta

rustc --version --verbose:

$ rustc --version --verbose
rustc 1.42.0 (b8cedc004 2020-03-09)
binary: rustc
commit-hash: b8cedc00407a4c56a3bda1ed605c6fc166655447
commit-date: 2020-03-09
host: x86_64-unknown-linux-gnu
release: 1.42.0
LLVM version: 9.0

Error output

<output>

Backtrace

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 11, kind: WouldBlock, message: "Resource temporarily unavailable" }', /rustc/b8
cedc00407a4c56a3bda1ed605c6fc166655447/src/librustc_interface/util.rs:127:11
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:77
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:59
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1052
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1426
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:62
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:204
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:224
  10: rustc_driver::report_ice
  11: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:476
  12: rust_begin_unwind
             at src/libstd/panicking.rs:380
  13: core::panicking::panic_fmt
             at src/libcore/panicking.rs:85
  14: core::option::expect_none_failed
             at src/libcore/option.rs:1199
  15: rustc_interface::util::spawn_thread_pool
  16: rustc_driver::run_compiler
  17: std::panicking::try::do_call
  18: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:86
  19: rustc_driver::catch_fatal_errors
  20: rustc_driver::main
  21: std::rt::lang_start::{{closure}}
  22: std::rt::lang_start_internal::{{closure}}
             at src/libstd/rt.rs:52
  23: std::panicking::try::do_call
             at src/libstd/panicking.rs:305
  24: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:86
  25: std::panicking::try
             at src/libstd/panicking.rs:281
  26: std::panic::catch_unwind
             at src/libstd/panic.rs:394
  27: std::rt::lang_start_internal
             at src/libstd/rt.rs:51
  28: main
  29: __libc_start_main
  30: <unknown>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: internal compiler error: unexpected panic

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.42.0 (b8cedc004 2020-03-09) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C incremental --crate-type lib

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
end of query stack

[jonas-schievink]

Looks like you ran into your process limit. Presumably rustc should exit with a fatal error when that happens instead of throwing an ICE?

[icy-ux]

Looks like you ran into your process limit. Presumably rustc should exit with a fatal error when that happens instead of throwing an ICE?

Yes. Even better if it's a clear and easy to understand fatal error message.

[jethrogb]

Got the same thing in rustc_codegen_ssa::back::write.

[Enselic]

This can be closed as a duplicate to #76452