Recursive struct hangs compilation on Nightly 03-19

[cengiz-io]

Hello!

I'm on OSX 10.11.3.

A recursive struct like this throws a nice error in stable

struct Line {
    start: Line,
    end: Line,
}

fn main() {
}

However, in 2016-03-19 it just hangs rustc.

I tried to gather some details using lldb

(lldb) process attach --pid 58606
Process 58606 stopped
* thread #1: tid = 0x3928a9, 0x00007fff9c49b206 libsystem_kernel.dylib`__semwait_signal + 10, queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
    frame #0: 0x00007fff9c49b206 libsystem_kernel.dylib`__semwait_signal + 10
libsystem_kernel.dylib`__semwait_signal:
->  0x7fff9c49b206 <+10>: jae    0x7fff9c49b210            ; <+20>
    0x7fff9c49b208 <+12>: movq   %rax, %rdi
    0x7fff9c49b20b <+15>: jmp    0x7fff9c495c02            ; cerror
    0x7fff9c49b210 <+20>: retq

Executable module set to "/usr/local/bin/rustc".
Architecture set to: x86_64h-apple-macosx.
(lldb) thread backtrace all
* thread #1: tid = 0x3928a9, 0x00007fff9c49b206 libsystem_kernel.dylib`__semwait_signal + 10, queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
  * frame #0: 0x00007fff9c49b206 libsystem_kernel.dylib`__semwait_signal + 10
    frame #1: 0x00007fff926e7c27 libsystem_pthread.dylib`pthread_join + 444
    frame #2: 0x000000010ae5955e libstd-18402db3.dylib`sys::thread::Thread::join::h0209efa0d5ad7236czy + 14
    frame #3: 0x0000000106961325 librustc_driver-18402db3.dylib`run::h6b4b5eb66973e302OLc + 2725
    frame #4: 0x000000010698921b librustc_driver-18402db3.dylib`main::h714cd508a226d964R0d + 1115
    frame #5: 0x000000010ae59aa3 libstd-18402db3.dylib`sys_common::unwind::try::try_fn::h12338358783828243857 + 35
    frame #6: 0x000000010ae4e79c libstd-18402db3.dylib`__rust_try + 12
    frame #7: 0x000000010ae59959 libstd-18402db3.dylib`rt::lang_start::h59eb5c015962608228y + 505
    frame #8: 0x000000010695aec4 rustc`start + 52

  thread #2: tid = 0x3928aa, 0x0000000107867173 librustc-18402db3.dylib`middle::subst::Substs$LT$$u27$tcx$GT$...std..hash..Hash::hash::h930124296078282112 + 563, name = 'rustc'
    frame #0: 0x0000000107867173 librustc-18402db3.dylib`middle::subst::Substs$LT$$u27$tcx$GT$...std..hash..Hash::hash::h930124296078282112 + 563
    frame #1: 0x000000010787f9a1 librustc-18402db3.dylib`collections::hash::set::HashSet$LT$T$C$$u20$S$GT$::insert::h16525620572284354841 + 129
    frame #2: 0x0000000107881044 librustc-18402db3.dylib`iter::FilterMap$LT$I$C$$u20$F$GT$.Iterator::next::h10479979705998296605 + 2836
    frame #3: 0x000000010787e7fd librustc-18402db3.dylib`middle::traits::fulfill::process_predicate::hc70860709ec86ab05US + 11293
    frame #4: 0x000000010787aa84 librustc-18402db3.dylib`obligation_forest::ObligationForest$LT$O$C$$u20$T$GT$::process_obligations::h18416070063450621727 + 420
    frame #5: 0x000000010787619d librustc-18402db3.dylib`middle::traits::fulfill::FulfillmentContext$LT$$u27$tcx$GT$::select_where_possible::h817133e3c0e6314baNS + 285
    frame #6: 0x0000000107317355 librustc_typeck-18402db3.dylib`check::FnCtxt$LT$$u27$a$C$$u20$$u27$tcx$GT$::select_obligations_where_possible::h7ea8359c24588fcdiMq + 69
    frame #7: 0x0000000107316a76 librustc_typeck-18402db3.dylib`check::FnCtxt$LT$$u27$a$C$$u20$$u27$tcx$GT$::select_all_obligations_and_apply_defaults::hb16d7cdeef868ac5Ayq + 9606
    frame #8: 0x000000010731768c librustc_typeck-18402db3.dylib`check::FnCtxt$LT$$u27$a$C$$u20$$u27$tcx$GT$::select_all_obligations_or_error::hfdec5f3d4f35bfa6bKq + 60
    frame #9: 0x000000010730df67 librustc_typeck-18402db3.dylib`check::wfcheck::CheckTypeWellFormedVisitor$LT$$u27$ccx$C$$u20$$u27$tcx$GT$.Visitor$LT$$u27$v$GT$::visit_item::h70c5a6a8c34d93e9uXk + 4375
    frame #10: 0x0000000107303ad0 librustc_typeck-18402db3.dylib`check::check_wf_new::h46828c06d7effb2dTIo + 816
    frame #11: 0x00000001072fb864 librustc_typeck-18402db3.dylib`check_crate::h3e3d779ef330fadcCFC + 3204
    frame #12: 0x00000001069a9db2 librustc_driver-18402db3.dylib`driver::phase_3_run_analysis_passes::_$u7b$$u7b$closure$u7d$$u7d$::closure.30095 + 146
    frame #13: 0x00000001069a83ea librustc_driver-18402db3.dylib`middle::ty::context::TyCtxt$LT$$u27$tcx$GT$::create_and_enter::h11812805895441873020 + 8282
    frame #14: 0x00000001069a4dae librustc_driver-18402db3.dylib`driver::phase_3_run_analysis_passes::h5261001332275006052 + 11550
    frame #15: 0x0000000106977df8 librustc_driver-18402db3.dylib`driver::compile_input::he5def18759d9424cPca + 8440
    frame #16: 0x00000001069656f7 librustc_driver-18402db3.dylib`run_compiler::h61ff55f691b932efVMc + 4023
    frame #17: 0x0000000106962ca3 librustc_driver-18402db3.dylib`sys_common::unwind::try::try_fn::h2984156204492186173 + 467
    frame #18: 0x000000010ae4e79c libstd-18402db3.dylib`__rust_try + 12
    frame #19: 0x000000010ae4e724 libstd-18402db3.dylib`sys_common::unwind::inner_try::hbef67b929e699248JDt + 116
    frame #20: 0x000000010696353a librustc_driver-18402db3.dylib`boxed::F.FnBox$LT$A$GT$::call_box::h8793623295134616532 + 394
    frame #21: 0x000000010ae592c9 libstd-18402db3.dylib`sys::thread::Thread::new::thread_start::h68477ad6a3ba8036fvy + 57
    frame #22: 0x00007fff926e6c13 libsystem_pthread.dylib`_pthread_body + 131
    frame #23: 0x00007fff926e6b90 libsystem_pthread.dylib`_pthread_start + 168
    frame #24: 0x00007fff926e4375 libsystem_pthread.dylib`thread_start + 13

Thanks for the great work!

[aturon]

cc @nikomatsakis

[nikomatsakis]

dup of #32326 -- thanks for the report!