using mold results into panic

[domenkozar]

Code

1. Install Nix: https://devenv.sh/getting-started/#1-install-nix
2. Install devenv: nix-env -iA devenv -f https://github.com/NixOS/nixpkgs/tarball/476a33c53da66a2a77a89bb9bcf54d5e3c232c3d
3. git clone https://github.com/cachix/devenv
4. git checkout rust-mold
5. devenv shell cargo build

Error output

   Compiling devenv-run-tests v0.1.0 (/home/domen/dev/cachix/devenv/devenv-run-tests)
thread 'rustc' panicked at library/alloc/src/raw_vec.rs:571:5:
capacity overflow
stack backtrace:
   0:     0x7f6e2ef59117 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hc7227e0e319a0b38
   1:     0x7f6e2ef8f310 - core::fmt::write::hab7a2cb9fb1eea10
   2:     0x7f6e2ef2988f - std::io::Write::write_fmt::h5d9ea37d99fc8ea3
   3:     0x7f6e2ef58ee4 - std::sys_common::backtrace::print::h7ef6b9088506adf3
   4:     0x7f6e2ef59dea - std::panicking::default_hook::{{closure}}::h2be91e085f955e55
   5:     0x7f6e2ef59b13 - std::panicking::default_hook::hd222121dd148ba89
   6:     0x7f6e2f7cc178 - std[6e8b80a297c52f92]::panicking::update_hook::<alloc[994071f8baacd75d]::boxed::Box<rustc_driver_impl[366a67edb31c7905]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x7f6e2ef5a548 - std::panicking::rust_panic_with_hook::hcb0f9a863644f6c2
   8:     0x7f6e2ef5a28e - std::panicking::begin_panic_handler::{{closure}}::hb3736c891f535df7
   9:     0x7f6e2ef59346 - std::sys_common::backtrace::__rust_end_short_backtrace::h5c867a2182e2e40a
  10:     0x7f6e2ef5a020 - rust_begin_unwind
  11:     0x7f6e2eefb745 - core::panicking::panic_fmt::h71234a7826c31033
  12:     0x7f6e2ef8463f - alloc::raw_vec::capacity_overflow::h9a6c4730fab6576f
  13:     0x7f6e315fb1cc - <rustc_query_system[66542c44af039fff]::dep_graph::serialized::SerializedDepGraph>::decode::<rustc_middle[8d00abeeb1ff241b]::dep_graph::DepsType>
  14:     0x7f6e315f8c2f - rustc_incremental[eeeac4218b780523]::persist::load::setup_dep_graph
  15:     0x7f6e2f9f8c34 - <rustc_interface[7e6b73ecb68df30f]::queries::Queries>::global_ctxt
  16:     0x7f6e2f79648a - <rustc_interface[7e6b73ecb68df30f]::interface::Compiler>::enter::<rustc_driver_impl[366a67edb31c7905]::run_compiler::{closure#0}::{closure#0}, core[d198b710c259850c]::result::Result<core[d198b710c259850c]::option::Option<rustc_interface[7e6b73ecb68df30f]::queries::Linker>, rustc_span[3e214166d8962b9f]::ErrorGuaranteed>>
  17:     0x7f6e2f77f4cc - rustc_span[3e214166d8962b9f]::set_source_map::<core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>, rustc_interface[7e6b73ecb68df30f]::interface::run_compiler<core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>, rustc_driver_impl[366a67edb31c7905]::run_compiler::{closure#0}>::{closure#0}::{closure#0}>
  18:     0x7f6e2f7bfb9c - <scoped_tls[522fde4e9369c00a]::ScopedKey<rustc_span[3e214166d8962b9f]::SessionGlobals>>::set::<rustc_interface[7e6b73ecb68df30f]::interface::run_compiler<core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>, rustc_driver_impl[366a67edb31c7905]::run_compiler::{closure#0}>::{closure#0}, core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>>
  19:     0x7f6e2f780c61 - rustc_span[3e214166d8962b9f]::create_session_globals_then::<core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>, rustc_interface[7e6b73ecb68df30f]::interface::run_compiler<core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>, rustc_driver_impl[366a67edb31c7905]::run_compiler::{closure#0}>::{closure#0}>
  20:     0x7f6e2f7da290 - std[6e8b80a297c52f92]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[7e6b73ecb68df30f]::util::run_in_thread_with_globals<rustc_interface[7e6b73ecb68df30f]::interface::run_compiler<core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>, rustc_driver_impl[366a67edb31c7905]::run_compiler::{closure#0}>::{closure#0}, core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>>
  21:     0x7f6e2f7cc707 - <<std[6e8b80a297c52f92]::thread::Builder>::spawn_unchecked_<rustc_interface[7e6b73ecb68df30f]::util::run_in_thread_with_globals<rustc_interface[7e6b73ecb68df30f]::interface::run_compiler<core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>, rustc_driver_impl[366a67edb31c7905]::run_compiler::{closure#0}>::{closure#0}, core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[d198b710c259850c]::result::Result<(), rustc_span[3e214166d8962b9f]::ErrorGuaranteed>>::{closure#1} as core[d198b710c259850c]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  22:     0x7f6e2ef13f25 - std::sys::unix::thread::Thread::new::thread_start::hdf0ce3dbe0807413
  23:     0x7f6e2ed5a383 - start_thread
  24:     0x7f6e2eddd00c - __clone3
  25:                0x0 - <unknown>

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

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.76.0 (07dca489a 2024-02-04) (built from a source tarball) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C incremental=[REDACTED] -C link-arg=-fuse-ld=/nix/store/6cd7g5a3xr5hgk5304ba05w4j3yf6b6m-mold-wrapper-2.4.1/bin/ld.mold

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

query stack during panic:
end of query stack
error: could not compile `devenv-run-tests` (bin "devenv-run-tests")
warning: build failed, waiting for other jobs to finish...

[domenkozar]

Nevermind, it seems that I passed some wrong CFLAGS.

[saethlin]

This looks like another truncated DepGraph file: #122245

It's possible you also passed some wrong CFLAGS but I don't think that makes this any less of a compiler bug. In any case, if you can't reproduce the crash that's fine, I've still added this example to my list of reports.

[domenkozar]

Thanks.