[GHC] #12230: Non-deterministic ghc-iserv terminated error

24 Jun 2016

      #12230: Non-deterministic ghc-iserv terminated error
-------------------------------------+-------------------------------------
           Reporter:  ezyang         |             Owner:  simonmar
               Type:  bug            |            Status:  new
           Priority:  highest        |         Milestone:  8.2.1
          Component:  GHCi           |           Version:  8.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 I noticed on a recent validate that I have been getting non-deterministic
 test failures due to external interpreter:

 {{{
 =====> T10891(ext-interp) 12 of 15 [0, 1, 0]
 [77/9256]
 cd "./th/T10891.run" &&  "/home/hs01/ezyang/ghc-validate/inplace/test
 spaces/ghc-stage2" -c T10891.h
 s -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts
 -fno-warn-missed-specialisatio
 ns -fshow-warning-groups -XTemplateHaskell -package template-haskell
 -fexternal-interpreter -v0 > T108
 91.comp.stderr 2>&1
 Compile failed (exit code 1) errors were:

 T10891.hs:30:3: error:
     • Exception when trying to run compile-time code:
         ghc-stage2: ghc-iserv terminated (-11)
       Code: let
               display :: Name -> Q ()
               display q = ...
             in
               do { display ''C;
                    display ''C';
                    .... }
     • In the untyped splice:
         $(let
             display :: Name -> Q ()
             display q = do { ... }
           in
             do { display ''C;
                  display ''C';
                  display ''C'';
                  .... })
 }}}

 More tests error the higher I crank up parallelism; on a recent full test
 run I got something like twenty failures of this kind when I have twelve
 threads.

 There are at least two problems here. The first is the actual failure, but
 the second is that there isn't enough diagnostic information here to tell
 what the actual problem is. Combined with the nondeterministic nature of
 this bug I'm not sure how to debug it.

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12230
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