ICE: fictitious type T in sizing_type_of()

[wizeman]

I'm using rustc from git, version 0.12.0-1635-g29e928f.

I'm not using unboxed closures in my code (as in other instances of similar ICEs), but I am using rust-peg as a compiler plugin.

I will try creating a minimal test case as soon as I can.

error: internal compiler error: fictitious type T in sizing_type_of()
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'Box<Any>', /tmp/nix-build-rustc-0.12.0-pre-1635-g29e928f.drv-0/git-export/src/libsyntax/diagnostic.rs:180

stack backtrace:
   1:     0x7f249d1b7930 - rt::backtrace::imp::write::h35b2a3a854fd16f79ay
   2:     0x7f249d1baa00 - failure::on_fail::h5fe3c62e890f9e33zDy
   3:     0x7f249ce0cc70 - unwind::begin_unwind_inner::h440e3770a18c57176Qc
   4:     0x7f249ace7d60 - unwind::begin_unwind::h10820045589999459983
   5:     0x7f249ace8490 - diagnostic::Handler::bug::hebcd311e68634e5eldG
   6:     0x7f249baffe70 - session::Session::bug::hb990c17d2da79641543
   7:     0x7f249d681d30 - trans::type_of::sizing_type_of::h8fb740b4eae7c48djmp
   8:     0x7f249d780760 - iter::IteratorExt::collect::h16976657945506944557
   9:     0x7f249d7a0f40 - trans::adt::mk_struct::hfb8f4cdfce684a16k8I
  10:     0x7f249d67a9a0 - trans::adt::represent_type::ha7a49fa8eb5a0d751EI
  11:     0x7f249d65ca70 - trans::base::trans_item::h846b57fe3c72b638Yav
  12:     0x7f249d725a80 - trans::base::trans_mod::h7f1b213460adfd01tgv
  13:     0x7f249d65ca70 - trans::base::trans_item::h846b57fe3c72b638Yav
  14:     0x7f249d725a80 - trans::base::trans_mod::h7f1b213460adfd01tgv
  15:     0x7f249d65ca70 - trans::base::trans_item::h846b57fe3c72b638Yav
  16:     0x7f249d725a80 - trans::base::trans_mod::h7f1b213460adfd01tgv
  17:     0x7f249d72c8b0 - trans::base::trans_crate::h032bd94b1afe9e1ci9v
  18:     0x7f249d7d9910 - driver::driver::phase_4_translate_to_llvm::h366c22cee2bd15adPwS
  19:     0x7f249d7c7130 - driver::driver::compile_input::he5771e0f4ccba38413R
  20:     0x7f249d84a360 - driver::run_compiler::hd483cb868d7c1178b2T
  21:     0x7f249d84a250 - driver::run::closure.60779
  22:     0x7f249d652100 - task::TaskBuilder::try_future::closure.39746
  23:     0x7f249d188580 - task::TaskBuilder::spawn_internal::closure.30919
  24:     0x7f249ce0aa40 - task::Task::spawn::closure.5760
  25:     0x7f249ce66c40 - rust_try_inner
  26:     0x7f249ce66c30 - rust_try
  27:     0x7f249ce0ab20 - unwind::try::h1427985e053e4733pFc
  28:     0x7f249ce0a8e0 - task::Task::run::h97de0ec0c6ae7160fOb
  29:     0x7f249ce0a4d0 - task::Task::spawn::closure.5736
  30:     0x7f249ce0bf20 - thread::thread_start::hfe7fdbc1c4a91439i6b
  31:     0x7f2497de0eb0 - start_thread
  32:     0x7f249cada089 - clone
  33:                0x0 - <unknown>

[wizeman]

Ok, here's the simplest test case I could come up with:

#![warn(variant_size_differences)]

#![feature(phase)]

#[phase(plugin)]
extern crate peg_syntax_ext;

peg! parser("")

fn main() {}

(Again, I am using the rust-peg library).

Apparently, if I remove the variant_size_differences warning, the error disappears...

[tamird]

Unable to repro this with slightly updated code:

#![warn(variant_size_differences)]
#![feature(collections, str_char, plugin)]
#![plugin(peg_syntax_ext)]

peg! parser("");

fn main() {}

Compiles without error. @steveklabnik close?

[steveklabnik]

Sounds good. @wizeman , please let me know if you're still seeing this.