thread 'rustc' panicked at 'called Result::unwrap() on an Err value: SourceNotAvailable

[Badel2]

I'm seeing an internal compiler error on the following input (found by fuzz-rustc):

Code

fn L(,,) {
    L(vec![])
}

Playground

Error output

error: expected parameter name, found `,`
 --> src/lib.rs:1:6
  |
1 | fn L(,,) {
  |      ^ expected parameter name

error: expected parameter name, found `,`
 --> src/lib.rs:1:7
  |
1 | fn L(,,) {
  |       ^ expected parameter name

thread 'rustc' panicked at 'called `Result::unwrap()` on an `Err` value: SourceNotAvailable { filename: Real(Remapped { local_path: None, virtual_name: "/rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/alloc/src/macros.rs" }) }', compiler/rustc_typeck/src/check/fn_ctxt/checks.rs:984:77

Caused by this line introduced in #92364

rust/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

Line 984 in 4ca19e0

let arg_text = source_map.span_to_snippet(arg_span).unwrap();

I found a similar issue in the past, this pull request fixes it: #70725

Unfortunately, this one looks like a spurious failure. It can be reproduced in the playground using nightly 2022-04-18, but when I try it locally using the same nightly version there is no ICE. This is the error message:

error: expected parameter name, found `,`
 --> src/lib.rs:1:6
  |
1 | fn L(,,) {
  |      ^ expected parameter name

error: expected parameter name, found `,`
 --> src/lib.rs:1:7
  |
1 | fn L(,,) {
  |       ^ expected parameter name

error[E0061]: this function takes 2 arguments but 1 argument was supplied
 --> src/lib.rs:2:5
  |
2 |     L(vec![])
  |     ^-------- an argument is missing
  |
note: function defined here
 --> src/lib.rs:1:4
  |
1 | fn L(,,) {
  |    ^--
help: provide the argument
  |
2 |     L($crate::vec::Vec::new(), {[type error]})
  |

Backtrace

   Compiling playground v0.0.1 (/playground)
error: expected parameter name, found `,`
 --> src/lib.rs:1:6
  |
1 | fn L(,,) {
  |      ^ expected parameter name

error: expected parameter name, found `,`
 --> src/lib.rs:1:7
  |
1 | fn L(,,) {
  |       ^ expected parameter name

thread 'rustc' panicked at 'called `Result::unwrap()` on an `Err` value: SourceNotAvailable { filename: Real(Remapped { local_path: None, virtual_name: "/rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/alloc/src/macros.rs" }) }', compiler/rustc_typeck/src/check/fn_ctxt/checks.rs:984:77
stack backtrace:
   0:     0x7fb944eff82d - std::backtrace_rs::backtrace::libunwind::trace::h9d7060c592fe8069
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7fb944eff82d - std::backtrace_rs::backtrace::trace_unsynchronized::hde51808b1556e5d1
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fb944eff82d - std::sys_common::backtrace::_print_fmt::hd954a2d1cd9fdbd5
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7fb944eff82d - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h6271b22d4e4423c8
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7fb944f5aecc - core::fmt::write::heb1c2a4e59b134a9
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/core/src/fmt/mod.rs:1194:17
   5:     0x7fb944ef1011 - std::io::Write::write_fmt::h6652729f1feeae87
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/io/mod.rs:1655:15
   6:     0x7fb944f02545 - std::sys_common::backtrace::_print::ha9ae153024491f3f
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7fb944f02545 - std::sys_common::backtrace::print::h110c021885084d6a
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7fb944f02545 - std::panicking::default_hook::{{closure}}::h68d23f0b88a08886
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/panicking.rs:295:22
   9:     0x7fb944f021b9 - std::panicking::default_hook::h2e20223d1536191d
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/panicking.rs:314:9
  10:     0x7fb9456a4731 - rustc_driver[46ea51695bd673e5]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7fb944f02d16 - std::panicking::rust_panic_with_hook::hfe1e95a000a88a64
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/panicking.rs:702:17
  12:     0x7fb944f02b17 - std::panicking::begin_panic_handler::{{closure}}::h04cf82910c0a653e
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/panicking.rs:588:13
  13:     0x7fb944effce4 - std::sys_common::backtrace::__rust_end_short_backtrace::h187f35deeb28abc2
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/sys_common/backtrace.rs:138:18
  14:     0x7fb944f02849 - rust_begin_unwind
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/panicking.rs:584:5
  15:     0x7fb944ec7ba3 - core::panicking::panic_fmt::h70547f234f37fa30
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/core/src/panicking.rs:142:14
  16:     0x7fb944ec7c93 - core::result::unwrap_failed::h95b8761ba0c00f97
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/core/src/result.rs:1785:5
  17:     0x7fb946b5123c - <rustc_typeck[1bd8200d7af772bc]::check::fn_ctxt::FnCtxt>::check_argument_types
  18:     0x7fb946b15f6e - <rustc_typeck[1bd8200d7af772bc]::check::fn_ctxt::FnCtxt>::confirm_builtin_call
  19:     0x7fb946b12438 - <rustc_typeck[1bd8200d7af772bc]::check::fn_ctxt::FnCtxt>::check_call
  20:     0x7fb946b6818d - <rustc_typeck[1bd8200d7af772bc]::check::fn_ctxt::FnCtxt>::check_expr_kind
  21:     0x7fb946b66fc0 - <rustc_typeck[1bd8200d7af772bc]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation
  22:     0x7fb946b56590 - <rustc_typeck[1bd8200d7af772bc]::check::fn_ctxt::FnCtxt>::check_block_with_expected
  23:     0x7fb946b682b3 - <rustc_typeck[1bd8200d7af772bc]::check::fn_ctxt::FnCtxt>::check_expr_kind
  24:     0x7fb946b66fc0 - <rustc_typeck[1bd8200d7af772bc]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation
  25:     0x7fb946c802d6 - rustc_typeck[1bd8200d7af772bc]::check::check::check_fn
  26:     0x7fb946be0140 - <rustc_infer[a51b2704175fce84]::infer::InferCtxtBuilder>::enter::<&rustc_middle[4038938c89644caa]::ty::context::TypeckResults, <rustc_typeck[1bd8200d7af772bc]::check::inherited::InheritedBuilder>::enter<rustc_typeck[1bd8200d7af772bc]::check::typeck_with_fallback<rustc_typeck[1bd8200d7af772bc]::check::typeck::{closure#0}>::{closure#1}, &rustc_middle[4038938c89644caa]::ty::context::TypeckResults>::{closure#0}>
  27:     0x7fb946bb2f00 - rustc_typeck[1bd8200d7af772bc]::check::typeck
  28:     0x7fb9470c7390 - rustc_query_system[103384a90f76de31]::query::plumbing::try_execute_query::<rustc_query_impl[8b18bc69f52059fc]::plumbing::QueryCtxt, rustc_query_system[103384a90f76de31]::query::caches::DefaultCache<rustc_span[8638436c65ab17fb]::def_id::LocalDefId, &rustc_middle[4038938c89644caa]::ty::context::TypeckResults>>
  29:     0x7fb9471cbb08 - <rustc_query_impl[8b18bc69f52059fc]::Queries as rustc_middle[4038938c89644caa]::ty::query::QueryEngine>::typeck
  30:     0x7fb946c64c18 - <rustc_middle[4038938c89644caa]::hir::map::Map>::par_body_owners::<rustc_typeck[1bd8200d7af772bc]::check::typeck_item_bodies::{closure#0}>
  31:     0x7fb94797f23c - rustc_typeck[1bd8200d7af772bc]::check::typeck_item_bodies
  32:     0x7fb947bd3c92 - rustc_query_system[103384a90f76de31]::query::plumbing::try_execute_query::<rustc_query_impl[8b18bc69f52059fc]::plumbing::QueryCtxt, rustc_query_system[103384a90f76de31]::query::caches::DefaultCache<(), ()>>
  33:     0x7fb947bfb4a1 - rustc_query_system[103384a90f76de31]::query::plumbing::get_query::<rustc_query_impl[8b18bc69f52059fc]::queries::typeck_item_bodies, rustc_query_impl[8b18bc69f52059fc]::plumbing::QueryCtxt>
  34:     0x7fb94798e2f3 - <rustc_session[5849b3ac9fc37c68]::session::Session>::time::<(), rustc_typeck[1bd8200d7af772bc]::check_crate::{closure#7}>
  35:     0x7fb94798be93 - rustc_typeck[1bd8200d7af772bc]::check_crate
  36:     0x7fb94770c477 - rustc_interface[668261b8f47f72c0]::passes::analysis
  37:     0x7fb947bc9dc4 - rustc_query_system[103384a90f76de31]::query::plumbing::try_execute_query::<rustc_query_impl[8b18bc69f52059fc]::plumbing::QueryCtxt, rustc_query_system[103384a90f76de31]::query::caches::DefaultCache<(), core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>>>
  38:     0x7fb947c0b24e - rustc_query_system[103384a90f76de31]::query::plumbing::get_query::<rustc_query_impl[8b18bc69f52059fc]::queries::analysis, rustc_query_impl[8b18bc69f52059fc]::plumbing::QueryCtxt>
  39:     0x7fb9476e9af7 - <rustc_interface[668261b8f47f72c0]::passes::QueryContext>::enter::<rustc_driver[46ea51695bd673e5]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>>
  40:     0x7fb9476d5078 - <rustc_interface[668261b8f47f72c0]::interface::Compiler>::enter::<rustc_driver[46ea51695bd673e5]::run_compiler::{closure#1}::{closure#2}, core[2fe9dabce7a4eee7]::result::Result<core[2fe9dabce7a4eee7]::option::Option<rustc_interface[668261b8f47f72c0]::queries::Linker>, rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>>
  41:     0x7fb9476fde3f - rustc_span[8638436c65ab17fb]::with_source_map::<core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>, rustc_interface[668261b8f47f72c0]::interface::create_compiler_and_run<core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>, rustc_driver[46ea51695bd673e5]::run_compiler::{closure#1}>::{closure#1}>
  42:     0x7fb9476d5c97 - <scoped_tls[b360d135f6f091a9]::ScopedKey<rustc_span[8638436c65ab17fb]::SessionGlobals>>::set::<rustc_interface[668261b8f47f72c0]::interface::run_compiler<core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>, rustc_driver[46ea51695bd673e5]::run_compiler::{closure#1}>::{closure#0}, core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>>
  43:     0x7fb9476eb1df - std[4fdfe6e28689bcfc]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[668261b8f47f72c0]::util::run_in_thread_pool_with_globals<rustc_interface[668261b8f47f72c0]::interface::run_compiler<core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>, rustc_driver[46ea51695bd673e5]::run_compiler::{closure#1}>::{closure#0}, core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>>::{closure#0}, core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>>
  44:     0x7fb9476eb329 - <<std[4fdfe6e28689bcfc]::thread::Builder>::spawn_unchecked_<rustc_interface[668261b8f47f72c0]::util::run_in_thread_pool_with_globals<rustc_interface[668261b8f47f72c0]::interface::run_compiler<core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>, rustc_driver[46ea51695bd673e5]::run_compiler::{closure#1}>::{closure#0}, core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>>::{closure#0}, core[2fe9dabce7a4eee7]::result::Result<(), rustc_errors[87e4665ca07ec85e]::ErrorGuaranteed>>::{closure#1} as core[2fe9dabce7a4eee7]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  45:     0x7fb944f0cbc3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h6caff75e9500dfec
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/alloc/src/boxed.rs:1866:9
  46:     0x7fb944f0cbc3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hfcb7dd749eba4870
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/alloc/src/boxed.rs:1866:9
  47:     0x7fb944f0cbc3 - std::sys::unix::thread::Thread::new::thread_start::h865210c19e650802
                               at /rustc/311e2683e1bad87715b1558f7900e294d24ce491/library/std/src/sys/unix/thread.rs:108:17
  48:     0x7fb944e3d609 - start_thread
  49:     0x7fb944d56163 - clone
  50:                0x0 - <unknown>

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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.62.0-nightly (311e2683e 2022-04-18) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2

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

query stack during panic:
#0 [typeck] type-checking `L`
#1 [typeck_item_bodies] type-checking all item bodies
#2 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `playground` due to 2 previous errors

[matthiaskrgr]

Is this still reproducible? I didn't get the ICE, maybe theres some extra flags needed?

[Badel2]

The playground seems to reliably reproduce it. And I can reproduce it sometimes using cargo-bisect-rustc:

cargo bisect-rustc --test-dir=. --start=2022-04-16 --end=2022-04-23 --prompt

But that is not always reliable. Given that the error message is "SourceNotAvailable", I guess this is related to how the toolchain is installed (the rust-src component?). Because at one point I tried the latest nightly with cargo-bisect-rustc and it did not ICE, but some days later I tried the same nightly using the same command and it did ICE.

But I would just assume that while there is an unwrap in the code this issue is not fixed.

[araruna]

I'm currently using rustc 1.62.0-nightly (055bf4c 2022-04-25) and from the 10 times I tried executing the code, all of them generated an ICE.

[kaimast]

I think I see this issue too. I also had to go back to 2022-04-18 to be able to compile my code.

[Badel2]

I opened a pull request with a one line change that may fix this, but I have no way to reproduce it locally (compiling the example code works fine even without the changes of that pull request). The playground can still reproduce the issue as of nightly 2022-04-29, so we can use it to check if this issue is really fixed after that pull request is merged.