compiler panic using nightly on rustc_typeck::check::compare_method::compare_impl_method::_{{closure}}::h08bef90d287aed42

[seppo0010]

I'm not quite sure if what I'm doing is correct, but since I got a compiler panic I thought I should report it. You can download the full project from here https://github.com/seppo0010/limitd-rs/tree/rustc-crash ; I created a tag to point to the commit that reproduces the crash.

The relevant code is probably within this function definition

    fn put(&self, key: &[u8], value: &[u8]) -> Box<Future<Item=(), Error=Error>> {
        let mut opts = Options::new();
        opts.create_if_missing = true;
        let db = match LDatabase::open(Path::new(&*self.path), opts) {
            Ok(db) => Box::new(db),
            Err(e) => { panic!("failed to open database: {:?}", e) }
        };
        let write_opts = WriteOptions::new();
        match db.put(write_opts, key, value) {
            Ok(_) => { return finished(()).boxed() },
            Err(e) => { return failed(Error::LevelDBError(e)).boxed() }
        }
    }

This is my rustc version

rustc --version --verbose
rustc 1.13.0-nightly (f883b0bba 2016-08-19)
binary: rustc
commit-hash: f883b0bbab6c433eb7b7042b605b4339022c563a
commit-date: 2016-08-19
host: x86_64-unknown-linux-gnu
release: 1.13.0-nightly

and the build command with the backtrace

RUST_BACKTRACE=1 cargo build --verbose
       Fresh slab v0.2.0 (https://github.com/carllerche/slab?rev=5476efcafb#5476efca)
       Fresh void v1.0.2
       Fresh semver v0.1.20
       Fresh winapi-build v0.1.1
       Fresh slab v0.2.0
       Fresh libc v0.2.15
       Fresh scoped-tls v0.1.0
       Fresh db-key v0.0.5
       Fresh winapi v0.2.8
       Fresh utf8-ranges v0.1.3
       Fresh getopts v0.2.14
       Fresh bitflags v0.4.0
       Fresh memchr v0.1.11
       Fresh protobuf v1.0.23
       Fresh db-key v0.1.0
       Fresh cfg-if v0.1.0
       Fresh regex-syntax v0.3.4
       Fresh aho-corasick v0.5.2
       Fresh log v0.3.6
       Fresh leveldb-sys v2.0.0
       Fresh net2 v0.2.26
       Fresh kernel32-sys v0.2.2
       Fresh futures v0.1.0 (https://github.com/alexcrichton/futures-rs?rev=71801dc#71801dcd)
       Fresh leveldb v0.8.3
       Fresh rustc_version v0.1.7
       Fresh time v0.1.35
       Fresh futures-io v0.1.0 (https://github.com/alexcrichton/futures-rs?rev=71801dc#71801dcd)
       Fresh thread-id v2.0.0
       Fresh thread_local v0.2.6
       Fresh regex v0.1.73
       Fresh env_logger v0.3.4
       Fresh nix v0.6.0
       Fresh mio v0.6.0-dev (https://github.com/carllerche/mio#00e19dd6)
       Fresh futures-mio v0.1.0 (https://github.com/alexcrichton/futures-rs?rev=71801dc#71801dcd)
   Compiling limitd-rs v0.1.0 (file:///home/seppo/Projects/limitd-rs)
     Running `rustc src/main.rs --crate-name limitd_rs --crate-type bin -g -C metadata=137628deb0353257 --out-dir /home/seppo/Projects/limitd-rs/target/debug --emit=dep-info,link -L dependency=/home/seppo/Projects/limitd-rs/target/debug/deps --extern futures_mio=/home/seppo/Projects/limitd-rs/target/debug/deps/libfutures_mio-3c1106ba38a0682a.rlib --extern leveldb=/home/seppo/Projects/limitd-rs/target/debug/deps/libleveldb-497869f359049725.rlib --extern net2=/home/seppo/Projects/limitd-rs/target/debug/deps/libnet2-755d3e4f87237d0e.rlib --extern time=/home/seppo/Projects/limitd-rs/target/debug/deps/libtime-750bfdd52feafcb7.rlib --extern log=/home/seppo/Projects/limitd-rs/target/debug/deps/liblog-bf16bb9a4912b11d.rlib --extern env_logger=/home/seppo/Projects/limitd-rs/target/debug/deps/libenv_logger-2296687296dd1e8e.rlib --extern futures_io=/home/seppo/Projects/limitd-rs/target/debug/deps/libfutures_io-20978b51499790d1.rlib --extern getopts=/home/seppo/Projects/limitd-rs/target/debug/deps/libgetopts-33691dbdf8852281.rlib --extern futures=/home/seppo/Projects/limitd-rs/target/debug/deps/libfutures-0ff68d58cf5da702.rlib --extern protobuf=/home/seppo/Projects/limitd-rs/target/debug/deps/libprotobuf-6820fc0a7d02519c.rlib --extern db_key=/home/seppo/Projects/limitd-rs/target/debug/deps/libdb_key-3e97f27935b69eb3.rlib -L native=/home/seppo/Projects/limitd-rs/target/debug/build/leveldb-sys-c084cdddf63c7867/out`
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: run with `RUST_BACKTRACE=1` for a backtrace

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', ../src/libcore/option.rs:326
stack backtrace:
   1:     0x7f8d0fea7de9 - std::sys::backtrace::tracing::imp::write::h482d45d91246faa2
   2:     0x7f8d0feb84dc - std::panicking::default_hook::_{{closure}}::h89158f66286b674e
   3:     0x7f8d0feb67e7 - std::panicking::default_hook::h9e30d428ee3b0c43
   4:     0x7f8d0feb6ff8 - std::panicking::rust_panic_with_hook::h2224f33fb7bf2f4c
   5:     0x7f8d0feb6e92 - std::panicking::begin_panic::hcb11a4dc6d779ae5
   6:     0x7f8d0feb6dc0 - std::panicking::begin_panic_fmt::h310416c62f3935b3
   7:     0x7f8d0feb6d41 - rust_begin_unwind
   8:     0x7f8d0ff2240f - core::panicking::panic_fmt::hc5789f4e80194729
   9:     0x7f8d0ff2233b - core::panicking::panic::h1953378f4b37b561
  10:     0x7f8d0e59bf3c - rustc_typeck::check::compare_method::compare_impl_method::_{{closure}}::h08bef90d287aed42
  11:     0x7f8d0e4f8099 - rustc_typeck::check::compare_method::compare_impl_method::he3538453c2efe177
  12:     0x7f8d0e50cde2 - rustc_typeck::check::check_impl_items_against_trait::hb105ca8bb42a0b3d
  13:     0x7f8d0e50a5a2 - rustc_typeck::check::check_item_type::hba3733559d49be1e
  14:     0x7f8d0e502deb - _<rustc_typeck..check..CheckItemTypesVisitor<'a, 'tcx> as rustc..hir..intravisit..Visitor<'tcx>>::visit_item::h369cacffbaa18923
  15:     0x7f8d0e504ceb - rustc_typeck::check::check_item_types::h81e44a5d40f450fd
  16:     0x7f8d0e57c323 - rustc_typeck::check_crate::h8ec8b2f490f5dc28
  17:     0x7f8d10297b03 - rustc_driver::driver::phase_3_run_analysis_passes::_{{closure}}::h45e03cee16dcf298
  18:     0x7f8d10264546 - rustc_driver::driver::phase_3_run_analysis_passes::hc0de40cea97d81a1
  19:     0x7f8d10250f02 - rustc_driver::driver::compile_input::hd9ecc57abd3cba85
  20:     0x7f8d10283756 - rustc_driver::run_compiler::h184264500271cc39
  21:     0x7f8d101c98c2 - std::panicking::try::do_call::h17a7a17ad7240c5c
  22:     0x7f8d0fec6846 - __rust_maybe_catch_panic
  23:     0x7f8d101e326a - _<F as alloc..boxed..FnBox<A>>::call_box::h93f9128277b2964a
  24:     0x7f8d0feb4bb2 - std::sys::thread::Thread::new::thread_start::he0bf102845911132
  25:     0x7f8d081cd181 - start_thread
  26:     0x7f8d0faef47c - __clone
  27:                0x0 - <unknown>

error: Could not compile `limitd-rs`.

Caused by:
  Process didn't exit successfully: `rustc src/main.rs --crate-name limitd_rs --crate-type bin -g -C metadata=137628deb0353257 --out-dir /home/seppo/Projects/limitd-rs/target/debug --emit=dep-info,link -L dependency=/home/seppo/Projects/limitd-rs/target/debug/deps --extern futures_mio=/home/seppo/Projects/limitd-rs/target/debug/deps/libfutures_mio-3c1106ba38a0682a.rlib --extern leveldb=/home/seppo/Projects/limitd-rs/target/debug/deps/libleveldb-497869f359049725.rlib --extern net2=/home/seppo/Projects/limitd-rs/target/debug/deps/libnet2-755d3e4f87237d0e.rlib --extern time=/home/seppo/Projects/limitd-rs/target/debug/deps/libtime-750bfdd52feafcb7.rlib --extern log=/home/seppo/Projects/limitd-rs/target/debug/deps/liblog-bf16bb9a4912b11d.rlib --extern env_logger=/home/seppo/Projects/limitd-rs/target/debug/deps/libenv_logger-2296687296dd1e8e.rlib --extern futures_io=/home/seppo/Projects/limitd-rs/target/debug/deps/libfutures_io-20978b51499790d1.rlib --extern getopts=/home/seppo/Projects/limitd-rs/target/debug/deps/libgetopts-33691dbdf8852281.rlib --extern futures=/home/seppo/Projects/limitd-rs/target/debug/deps/libfutures-0ff68d58cf5da702.rlib --extern protobuf=/home/seppo/Projects/limitd-rs/target/debug/deps/libprotobuf-6820fc0a7d02519c.rlib --extern db_key=/home/seppo/Projects/limitd-rs/target/debug/deps/libdb_key-3e97f27935b69eb3.rlib -L native=/home/seppo/Projects/limitd-rs/target/debug/build/leveldb-sys-c084cdddf63c7867/out` (exit code: 101)

Thanks!

[TimNN]

Minimized:

trait Foo {
    fn foo(&self, &str);
}

struct Bar;

impl Foo for Bar {
    fn foo(&self, _: &[u8]) {}
}

fn main() {}

Actual Error:

error[E0053]: method `foo` has an incompatible type for trait
 --> <anon>:8:5
  |
8 |     fn foo(&self, _: &[u8]) {}
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected str, found slice
  |
  = note: expected type `fn(&Bar, &str)`
  = note:    found type `fn(&Bar, &[u8])`

Regression from beta / stable to nightly.

[TimNN]

Nightly nightly-2016-08-18 is still fine, nightly-2016-08-19 first shows the ICE.

[TimNN]

I assume this was introduced by #35765.

[TimNN]

A bit more simplified (no need for slices, any reference will do):

trait Foo {
    fn foo(&self, &u8);
}

struct Bar;

impl Foo for Bar {
    fn foo(&self, _: &u16) {}
}

fn main() {}

[frewsxcv]

Addressed by #35877