bootstrap: index out of bounds: the len is 1 but the index is 1', src/librustc_metadata/rmeta/decoder.rs:341:61

[matthiaskrgr]

This happened while bootstrapping std, rustc @ 7e11379

Error output

Building stage1 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
   Compiling std v0.0.0 (/home/matthias/vcs/github/rust/src/libstd)
thread 'rustc' panicked at 'index out of bounds: the len is 1 but the index is 1', src/librustc_metadata/rmeta/decoder.rs:341:61

Backtrace

Updating only changed submodules
Submodules updated in 0.03 seconds
    Finished dev [unoptimized + debuginfo] target(s) in 0.12s
Building stage0 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.19s
Copying stage0 std from stage0 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu / x86_64-unknown-linux-gnu)
Building stage0 compiler artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.17s
Copying stage0 rustc from stage0 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu / x86_64-unknown-linux-gnu)
Assembling stage1 compiler (x86_64-unknown-linux-gnu)
Building stage1 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
   Compiling std v0.0.0 (/home/matthias/vcs/github/rust/src/libstd)
thread 'rustc' panicked at 'index out of bounds: the len is 1 but the index is 1', src/librustc_metadata/rmeta/decoder.rs:341:61
stack backtrace:
   0: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
   1: core::fmt::write
   2: std::io::Write::write_fmt
   3: std::panicking::default_hook::{{closure}}
   4: std::panicking::default_hook
   5: rustc_driver::report_ice
   6: std::panicking::rust_panic_with_hook
   7: rust_begin_unwind
   8: core::panicking::panic_fmt
   9: core::panicking::panic_bounds_check
  10: rustc_metadata::rmeta::decoder::__ty_decoder_impl::<impl rustc_serialize::serialize::SpecializedDecoder<rustc_span::def_id::CrateNum> for rustc_metadata::rmeta::decoder::DecodeContext>::specialized_decode
  11: <T as rustc_serialize::serialize::Decodable>::decode
  12: rustc_serialize::serialize::Decoder::read_option
  13: rustc_metadata::rmeta::decoder::__ty_decoder_impl::<impl rustc_serialize::serialize::SpecializedDecoder<&rustc_middle::ty::sty::Const> for rustc_metadata::rmeta::decoder::DecodeContext>::specialized_decode
  14: rustc_metadata::rmeta::decoder::__ty_decoder_impl::<impl rustc_serialize::serialize::SpecializedDecoder<&rustc_middle::ty::TyS> for rustc_metadata::rmeta::decoder::DecodeContext>::specialized_decode
  15: rustc_metadata::rmeta::decoder::<impl rustc_metadata::creader::CrateMetadataRef>::get_type
  16: rustc_metadata::rmeta::decoder::cstore_impl::provide_extern::type_of
  17: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  18: rustc_query_system::query::plumbing::get_query_impl
  19: rustc_middle::ty::trait_def::trait_impls_of_provider::{{closure}}
  20: rustc_middle::ty::trait_def::trait_impls_of_provider
  21: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::trait_impls_of>::compute
  22: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  23: rustc_query_system::query::plumbing::get_query_impl
  24: rustc_middle::ty::trait_def::<impl rustc_middle::ty::context::TyCtxt>::all_impls
  25: rustc_trait_selection::traits::specialize::specialization_graph_provider
  26: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::specialization_graph_of>::compute
  27: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  28: rustc_query_system::query::plumbing::get_query_impl
  29: rustc_middle::ty::trait_def::TraitDef::ancestors
  30: rustc_typeck::impl_wf_check::min_specialization::check_min_specialization
  31: <rustc_typeck::impl_wf_check::ImplWfCheck as rustc_hir::itemlikevisit::ItemLikeVisitor>::visit_item
  32: rustc_middle::hir::map::Map::visit_item_likes_in_module
  33: rustc_typeck::impl_wf_check::check_mod_impl_wf
  34: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::check_mod_impl_wf>::compute
  35: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  36: rustc_query_system::query::plumbing::get_query_impl
  37: rustc_query_system::query::plumbing::ensure_query_impl
  38: rustc_typeck::impl_wf_check::impl_wf_check
  39: rustc_typeck::check_crate
  40: rustc_interface::passes::analysis
  41: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute
  42: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  43: rustc_middle::ty::query::plumbing::<impl rustc_query_system::query::QueryContext for rustc_middle::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}}::{{closure}}
  44: rustc_query_system::query::plumbing::get_query_impl::{{closure}}
  45: rustc_query_system::query::plumbing::get_query_impl
  46: rustc_middle::ty::context::tls::enter_global
  47: rustc_interface::interface::create_compiler_and_run
  48: rustc_ast::attr::with_session_globals
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 1.46.0-dev running on x86_64-unknown-linux-gnu

note: compiler flags: -Z macro-backtrace -Z save-analysis -Z binary-dep-depinfo -Z force-unstable-if-unmarked -C prefer-dynamic -C opt-level=3 -C embed-bitcode=no -C codegen-units=4 -C debuginfo=0 -C target-cpu=native -C link-args=-Wl,-rpath,$ORIGIN/../lib -C prefer-dynamic -C embed-bitcode=yes --crate-type dylib --crate-type rlib

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

query stack during panic:

thread 'rustc' has overflowed its stack
fatal runtime error: stack overflow
sccache: Compile terminated by signal 6====================>           ] 31/38: std
error: could not compile `std`.

To learn more, run the command again with --verbose.
command did not execute successfully: "/home/matthias/vcs/github/rust/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "build" "--target" "x86_64-unknown-linux-gnu" "-Zbinary-dep-depinfo" "-j" "4" "--release" "--features" "panic-unwind backtrace profiler compiler-builtins-c" "--manifest-path" "/home/matthias/vcs/github/rust/src/libtest/Cargo.toml" "--message-format" "json-render-diagnostics"
expected success, got: exit code: 101
failed to run: /home/matthias/vcs/github/rust/build/bootstrap/debug/bootstrap build
Build completed unsuccessfully in 0:00:01

[jyn514]

This seems like a duplicate of #76720.

[jyn514]

@matthiaskrgr have you run into this since filing the issue?

[matthiaskrgr]

I think yes, but it was probably months ago and not recently.