rustc 1.34.0 panics when running "cargo clippy" and checking "combine" crate

[ancwrd1]

Platform: x86_64-unknown-linux-gnu
Version: 1.34.0
Error description: when running cargo clippy compiler panics. Compilation works fine though.

Backtrace:

Checking combine v3.8.1
thread 'rustc' panicked at 'begin <= end (617 <= 296) when slicing `pub)
            $(#[$derive])*
            struct $type_name;
            type PartialState = (());
            $(#[$attr])*
            fn $name [$($type_params)*]($($arg : $arg_type),*)($input_type) -> $output_type
                where [$($where_`[...]', src/libcore/str/mod.rs:2014:5
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:39
   1: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:70
   2: std::panicking::default_hook::{{closure}}
             at src/libstd/sys_common/backtrace.rs:58
             at src/libstd/panicking.rs:200
   3: std::panicking::default_hook
             at src/libstd/panicking.rs:215
   4: rustc::util::common::panic_hook
   5: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:482
   6: std::panicking::continue_panic_fmt
             at src/libstd/panicking.rs:385
   7: rust_begin_unwind
             at src/libstd/panicking.rs:312
   8: core::panicking::panic_fmt
             at src/libcore/panicking.rs:85
   9: core::str::slice_error_fail
             at src/libcore/str/mod.rs:0
  10: core::str::traits::<impl core::slice::SliceIndex<str> for core::ops::range::RangeFrom<usize>>::index::{{closure}}
  11: <clippy_lints::functions::Functions as rustc::lint::LateLintPass<'a, 'tcx>>::check_fn
  12: <rustc::lint::context::LateContext<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_fn
  13: rustc::hir::intravisit::walk_item
  14: <rustc::lint::context::LateContext<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_item
  15: <rustc::lint::context::LateContext<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_mod
  16: rustc::hir::intravisit::walk_item
  17: <rustc::lint::context::LateContext<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_item
  18: <rustc::lint::context::LateContext<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_mod
  19: rustc::hir::intravisit::walk_item
  20: <rustc::lint::context::LateContext<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_item
  21: <rustc::lint::context::LateContext<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_mod
  22: rustc::hir::intravisit::walk_crate
  23: rustc::lint::context::check_crate
  24: rustc_driver::driver::phase_3_run_analysis_passes::{{closure}}::{{closure}}
  25: rustc::util::common::time
  26: <std::thread::local::LocalKey<T>>::with
  27: rustc::ty::context::TyCtxt::create_and_enter
  28: rustc_driver::driver::compile_input
  29: rustc_driver::run_compiler_with_pool
  30: <scoped_tls::ScopedKey<T>>::set
  31: rustc_driver::run_compiler
  32: <scoped_tls::ScopedKey<T>>::set
  33: syntax::with_globals
  34: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:87
  35: <F as alloc::boxed::FnBox<A>>::call_box
  36: std::sys::unix::thread::Thread::new::thread_start
             at /rustc/91856ed52c58aa5ba66a015354d1cc69e9779bdf/src/liballoc/boxed.rs:759
             at src/libstd/sys_common/thread.rs:14
             at src/libstd/sys/unix/thread.rs:81
  37: start_thread
  38: __GI___clone
query stack during panic:
end of query stack

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 1.34.0 (91856ed52 2019-04-10) running on x86_64-unknown-linux-gnu

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

[pietroalbini]

cc @oli-obk @Manishearth
Checked and this regressed from 1.33 to 1.34, but it's fixed on beta/nightly. Any idea on which PR could have fixed it?

@rustbot modify labels: regression-from-stable-to-stable T-dev-tools I-nominated I-ICE

[phansch]

@pietroalbini This was fixed in rust-lang/rust-clippy#3805

[pietroalbini]

Nominating that PR to be backported to stable.

cc @rust-lang/release
@rustbot modify labels: stable-nominated.

[Indy2222]

I have encountered a similar error and I am not sure whether it is the same or a different issue. From Travis CI:

$ cargo clippy -- -D warnings
    Checking num-traits v0.2.2
    Checking unicode-width v0.1.4
    Checking bitflags v1.0.1
thread 'rustc' panicked at 'begin <= end (190 <= 0) when slicing `}
                        }
                    )+
                }
                let mut first = true;
                $(
                    if <$BitFlags as __BitFlags>::$Flag(self) {
                        if !first {
                            t`[...]', src/libcore/str/mod.rs:2014:5
note: Run with `RUST_BACKTRACE=1` environment variable to display a 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 1.34.0 (91856ed52 2019-04-10) running on x86_64-unknown-linux-gnu
note: compiler flags: -C debuginfo=2 --crate-type lib
note: some of the compiler flags provided by cargo are hidden
error: Could not compile `bitflags`.
warning: build failed, waiting for other jobs to finish...
error: build failed
The command "cargo clippy -- -D warnings" exited with 101.

[pietroalbini]

cc @rust-lang/dev-tools, do you think this PR is safe to backport to a stable point release?

[Manishearth]

@pietroalbini Yep!

Feel free to make a stable branch on the clippy repo for this.

@oli-obk @phansch think we should also backport some of the redundant_closure fixes? Or move the lint to the nursery for now?

[Manishearth]

Made a backport PR in rust-lang/rust-clippy#4003

[Manishearth]

Both backported PRs already exist on beta.

[Manishearth]

@pietroalbini ready to go , see rust-lang/rust-clippy#4003

just check out the stable clippy branch.

[pietroalbini]

@Manishearth can the branch be called something like rust-1.34.1 (like Cargo does)? Otherwise the commits might go away if you reuse that branch for another point release in the future.

[Manishearth]

Done. I can also merge it back into mainline if necessary.

[pnkfelix]

removing nomination tag, as this appears to be well in hand.

[pietroalbini]

This should be fixed now.