Compile panic on nightly compiling `kamadak-exif`, assertion failed in byteorder

[sindreij]

I hope this is not already known, but my searching has not turned up anything.

Compiling a rust binary with the kamadak-exif dependency panices in nightly.

How to reproduce:

1. Create a new rust binary.
2. Add kamadak-exif = "0.3.0" to dependencies in Cargo.toml
3. Run RUST_BACKTRACE=1 cargo run

This gives the following output

   Compiling kamadak-exif v0.3.0
thread 'main' panicked at 'assertion failed: pack_size128(n as u128) <= nbytes && nbytes <= 16', /cargo/registry/src/github.com-1ecc6299db9ec823/byteorder-1.2.2/src/lib.rs:2128:9
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::print
             at libstd/sys_common/backtrace.rs:71
             at libstd/sys_common/backtrace.rs:59
   2: std::panicking::default_hook::{{closure}}
             at libstd/panicking.rs:211
   3: std::panicking::default_hook
             at libstd/panicking.rs:227
   4: rustc::util::common::panic_hook
   5: std::panicking::rust_panic_with_hook
             at libstd/panicking.rs:467
   6: std::panicking::begin_panic
   7: rustc::mir::interpret::write_target_uint
   8: <rustc_mir::interpret::memory::Memory<'a, 'mir, 'tcx, M>>::write_primval
   9: <rustc_mir::interpret::eval_context::EvalContext<'a, 'mir, 'tcx, M>>::write_value_to_ptr
  10: rustc_mir::interpret::const_eval::const_variant_index
  11: rustc_mir::hair::pattern::PatternContext::const_to_pat
  12: rustc_mir::hair::pattern::PatternContext::const_to_pat::{{closure}}
  13: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T, I>>::from_iter
  14: rustc_mir::hair::pattern::PatternContext::const_to_pat
  15: rustc_mir::hair::pattern::PatternContext::lower_path
  16: rustc_mir::hair::pattern::PatternContext::lower_pattern
  17: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &'a mut F>::call_once
  18: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T, I>>::from_iter
  19: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T, I>>::from_iter
  20: rustc_mir::hair::pattern::_match::MatchCheckCtxt::create_and_enter
  21: <rustc_mir::hair::pattern::check_match::MatchVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr
  22: <rustc_mir::hair::pattern::check_match::MatchVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr
  23: rustc::hir::intravisit::walk_block
  24: <rustc_mir::hair::pattern::check_match::MatchVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr
  25: rustc::hir::intravisit::walk_expr
  26: <rustc_mir::hair::pattern::check_match::MatchVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr
  27: <rustc_mir::hair::pattern::check_match::MatchVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_local
  28: rustc::hir::intravisit::walk_block
  29: <rustc_mir::hair::pattern::check_match::MatchVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr
  30: rustc::hir::intravisit::walk_block
  31: <rustc_mir::hair::pattern::check_match::MatchVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr
  32: <rustc_mir::hair::pattern::check_match::MatchVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_body
  33: rustc::session::Session::track_errors
  34: rustc_mir::hair::pattern::check_match::check_match
  35: rustc::dep_graph::graph::DepGraph::with_task_impl
  36: rustc::ty::context::tls::with_related_context
  37: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job
  38: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query
  39: rustc::hir::intravisit::Visitor::visit_nested_body
  40: rustc::hir::Crate::visit_all_item_likes
  41: rustc_mir::hair::pattern::check_match::check_crate
  42: rustc::util::common::time
  43: rustc::ty::context::tls::enter_context
  44: <std::thread::local::LocalKey<T>>::with
  45: rustc::ty::context::TyCtxt::create_and_enter
  46: rustc_driver::driver::compile_input
  47: rustc_driver::run_compiler_with_pool
  48: syntax::with_globals
  49: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  50: __rust_maybe_catch_panic
             at libpanic_unwind/lib.rs:105
  51: rustc_driver::run
  52: rustc_driver::main
  53: std::rt::lang_start::{{closure}}
  54: std::panicking::try::do_call
             at libstd/rt.rs:59
             at libstd/panicking.rs:310
  55: __rust_maybe_catch_panic
             at libpanic_unwind/lib.rs:105
  56: std::rt::lang_start_internal
             at libstd/panicking.rs:289
             at libstd/panic.rs:374
             at libstd/rt.rs:58
  57: main
  58: __libc_start_main
  59: <unknown>
query stack during panic:
#0 [check_match] processing `tiff::parse_ifd`
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 1.28.0-nightly (952f344cd 2018-05-18) 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 `kamadak-exif`.

To learn more, run the command again with --verbose.

It compiles on stable and beta.

Edit: Just running cargo build in https://github.com/kamadak/exif-rs gives the same result.

Meta

$ rustc --version --verbose
rustc 1.28.0-nightly (952f344cd 2018-05-18)
binary: rustc
commit-hash: 952f344cdc0bca58d9f6c54dcfbae0890246e886
commit-date: 2018-05-18
host: x86_64-unknown-linux-gnu
release: 1.28.0-nightly
LLVM version: 6.0

[sindreij]

Tried a few different nightlies. And it looks like it broke sometime between rustc 1.27.0-nightly (acd3871ba 2018-05-10) and rustc 1.27.0-nightly (ff2ac35db 2018-05-12)

This works

$ rustc --version --verbose
rustc 1.27.0-nightly (acd3871ba 2018-05-10)
binary: rustc
commit-hash: acd3871ba17316419c644e17547887787628ec2f
commit-date: 2018-05-10
host: x86_64-unknown-linux-gnu
release: 1.27.0-nightly
LLVM version: 6.0

This panics

$ rustc --version --verbose
rustc 1.27.0-nightly (ff2ac35db 2018-05-12)
binary: rustc
commit-hash: ff2ac35db93a80b2de5daa4f280bf1503d62c164
commit-date: 2018-05-12
host: x86_64-unknown-linux-gnu
release: 1.27.0-nightly
LLVM version: 6.0

[sindreij]

I have managed to get a much smaller example. Compiling this on nightly gives the above panic:

#[derive(PartialEq, Eq)]
pub struct Tag(pub Context, pub u16);

#[derive(PartialEq, Eq)]
pub enum Context {
    Tiff,
    Exif,
}

impl Tag {
    const ExifIFDPointer: Tag = Tag(Context::Tiff, 34665);
}

fn main() {
    match Tag::ExifIFDPointer {
        Tag::ExifIFDPointer => {}
    }
}

[sindreij]

Looks like it's fixed in the newest nightly (rustc 1.28.0-nightly (a3085756e 2018-05-19))

[kennytm]

Bisecting between acd3871...ff2ac35 gives #50249 as the regression PR.