ICE: assertion failed: did.krate != ast::LOCAL_CRATE

[matthewhammer]

The code below triggers an internal compiler error:

thread 'rustc' panicked at 'assertion failed: did.krate != ast::LOCAL_CRATE', /Users/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-mac/build/src/librustc/middle/ty.rs:5341

Smallest input file that tickles the error:

trait A<X> { }
trait B { type X; type Y : A<Self::X>; }
fn main () { }

When the bounds on Y are lifted, the bug goes away for me. That is, the following code compiles without an error:

trait A<X> { }
trait B { type X; type Y; }
fn main () { }

• Version info:

rustc 1.0.0-nightly (f1398d273 2015-01-31 20:21:02 +0000)
binary: rustc
commit-hash: f1398d2736f132dd4af828b3d9134691f924b7e1
commit-date: 2015-01-31 20:21:02 +0000
host: x86_64-apple-darwin
release: 1.0.0-nightly

• Backtrace:

stack backtrace:
   1:        0x10d966b27 - sys::backtrace::write::h1e2c8d6454da8cd1Xsu
   2:        0x10d98ccac - failure::on_fail::hc34cc2536b843a6dlwB
   3:        0x10d8ed878 - rt::unwind::begin_unwind_inner::hc1db7917310b1e46PdB
   4:        0x10a931c55 - rt::unwind::begin_unwind::h10851544081918456271
   5:        0x10ac96d80 - middle::ty::lookup_trait_def::h2256fffe21aabd99WH7
   6:        0x10acdbc17 - middle::ty::predicates_for_trait_ref::h5f31438d5452493c2I7
   7:        0x10acb3dcb - middle::traits::util::Elaborator<'cx, 'tcx>.Iterator::next::h8fa8483eadd3bbe7IgT
   8:        0x10acb9d94 - middle::traits::util::Supertraits<'cx, 'tcx>.Iterator::next::h55572798b69df69ajjT
   9:        0x10a5face7 - astconv::ast_ty_to_ty::closure.32964
  10:        0x10a594dc0 - astconv::ast_ty_to_ty::h28c37a0bcd64f3d22ru
  11:        0x10a5f0eed - vec::Vec<T>.FromIterator<T>::from_iter::h8194170135992664305
  12:        0x10a5ee9fe - astconv::convert_angle_bracketed_parameters::h14e1151854724c322zt
  13:        0x10a5f2d2b - astconv::ast_path_to_trait_ref::h8901deac3602014bVMt
  14:        0x10a5a081b - astconv::instantiate_trait_ref::haaed26dc31d8d3a8CJt
  15:        0x10a5f20ea - astconv::instantiate_poly_trait_ref::h5e153a7725bdcb786Ht
  16:        0x10a622fcb - collect::compute_bounds::hbff2a6aea3e3160byRw
  17:        0x10a60a5fd - collect::trait_def_of_item::hc2a893dcfe8940b96bw
  18:        0x10a608bdf - collect::CollectTraitDefVisitor<'a, 'tcx>.visit..Visitor<'v>::visit_item::haff1fcbfc2eb31abLmv
  19:        0x10a648c6f - check_crate::closure.34094
  20:        0x10a646c75 - check_crate::he1eddd9d21d7c627g8z
  21:        0x109ff6725 - driver::phase_3_run_analysis_passes::h5ea5b4fae09df7e4tGa
  22:        0x109fdcb9c - driver::compile_input::hfeebf01fd34be13bBba
  23:        0x10a0aa27e - run_compiler::h47834abf04acfba99ac
  24:        0x10a0a729f - thunk::F.Invoke<A, R>::invoke::h2084430363117493962
  25:        0x10a0a5f30 - rt::unwind::try::try_fn::h12547055720005252601
  26:        0x10da03b69 - rust_try_inner
  27:        0x10da03b56 - rust_try
  28:        0x10a0a65f4 - thunk::F.Invoke<A, R>::invoke::h838828363178605749
  29:        0x10d977333 - sys::thread::thread_start::h502153f3460908456lx
  30:     0x7fff951c02fc - _pthread_body
  31:     0x7fff951c0279 - _pthread_body

[nikomatsakis]

This is a dup of various other ICEs. A lot of people have been hitting this problem so I'm going to invest some energy into fixing it. I think it involves some non-trivial refactoring, unfortunately.

[edwardw]

cc me. #22338 seems to also fix this.

EDIT: nope, the bug simply doesn't exist any more on current master b63cee4.