[GHC] #16350: Nondeterministic T5559 failures on CI

[GHC]

#16350: Nondeterministic T5559 failures on CI
-------------------------------------+-------------------------------------
           Reporter:  RyanGlScott    |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.9
           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:
-------------------------------------+-------------------------------------
 The `T5559` test case occasionally fails on CI, forcing me to restart
 builds to get a green build status. Here is [https://ghc-
 gitlab.s3.amazonaws.com/6b/86/6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b/2019_02_21/31578/49824/job.log
 ?response-content-type=text/plain%3B%20charset%3Dutf-8&response-content-
 disposition=inline&X-Amz-Expires=600&X-Amz-Date=20190221T104600Z&X-Amz-
 Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAI3NPPHETCY4XXTOA/20190221
 /us-east-1/s3/aws4_request&X-Amz-SignedHeaders=host&X-Amz-
 Signature=4cda8d47d000a69a39765a5c141f1e33a610992f1f8ea60da83c4ec6eaca42d8
 one example] from a `validate-x86_64-linux-fedora27` run:

 {{{
 "gs" -dNODISPLAY -dBATCH -dQUIET -dNOPAUSE
 "profiling/should_run/T5559.run/T5559.ps"
 hp2ps output for T5559is not valid PostScript
 *** unexpected failure for T5559(profasm)

 <elided>

 SUMMARY for test run started at Thu Feb 21 00:32:08 2019 UTC
  0:44:16 spent to go through
     6839 total tests, which gave rise to
    26523 test cases, of which
    19210 were skipped

       42 had missing libraries
     7178 expected passes
       92 expected failures

        0 caused framework failures
        0 caused framework warnings
        0 unexpected passes
        1 unexpected failures
        0 unexpected stat failures

 Unexpected failures:
    profiling/should_run/T5559.run  T5559 [bad heap profile] (profasm)
 }}}

 Aside from the nondeterministic test failure, this also reveals a minor
 bug: it prints `T5559is not valid PostScript`, which should probably be
 `T5559 is not valid PostScript` instead.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16350>
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