[GHC] #15313: Framework failures on windows with plugins

[GHC]

#15313: Framework failures on windows with plugins
-------------------------------------+-------------------------------------
           Reporter:  simonpj        |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:  8.6.1
          Component:  Compiler       |           Version:  8.4.3
           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:
-------------------------------------+-------------------------------------
 On Windows, when the load is heavy (i.e. when doing a full `sh validate` I
 get a bunch of framework failures in the `plugins/` testsuite directory
 {{{
 Framework failures:
    plugins/plugins07.run             plugins07 [normal] (pre_cmd failed:
 2)
    plugins/T10420.run                T10420 [normal] (pre_cmd failed: 2)
    plugins/T11244.run                T11244 [normal] (pre_cmd failed: 2)
    plugins/plugin-recomp-pure.run    plugin-recomp-pure [normal] (pre_cmd
 failed: 2)
    plugins/plugin-recomp-impure.run  plugin-recomp-impure [normal]
 (pre_cmd failed: 2)
    plugins/plugin-recomp-flags.run   plugin-recomp-flags [normal] (pre_cmd
 failed: 2)
 }}}
 I sent a full log to Tamar who said:
 Thanks for the log, that does give a clue. The command fails with
 {{{
 setup.exe: 'C:/code/HEAD/inplace/bin/ghc-pkg.exe' exited with an error:
 ...
 rule-defining-plugin-0.1: cannot find any of
 ["libHSrule-defining-plugin-0.1-GxqqrdsQ5NRK9hAhEkvz8Z.a","libHSrule-
 defining-plugin-0.1-GxqqrdsQ5NRK9hAhEkvz8Z.p_a","libHSrule-defining-
 plugin-0.1-GxqqrdsQ5NRK9hAhEkvz8Z-ghc8.5.20180616.so","libHSrule-defining-
 plugin-0.1-GxqqrdsQ5NRK9hAhEkvz8Z-ghc8.5.20180616.dylib","HSrule-defining-
 plugin-0.1-GxqqrdsQ5NRK9hAhEkvz8Z-ghc8.5.20180616.dll"]
 on library path (use --force to override)

 make[2]: *** [Makefile:18: package.T10420] Error 1
 }}}
 so it's the `setup install` from
 https://github.com/ghc/ghc/blob/c2783ccf545faabd21a234a4dfc569cd856082b9/testsuite/tests/plugins
 /rule-defining-plugin/Makefile failing.

 Unfortunately, all those tests run with -v0 which is annoying because now
 the verbosity of the testsuite doesn't control that of these tests. I'm
 not sure why these commands fail under heavy load though.
 I'll need to dive into the source of ghc-pkg to figure out what's
 happening.

 Notice that all the framework failures are these plugin tests which modify
 a package database. A wild guess is that `ghc-pkg` tries to take a lock on
 all package-databases or something when it's mutating one. But I'm not
 intimately familiar with the package store and this doesn't explain why it
 doesn't happen on Linux.

 For now one solution I can propose is to create a ticket to track these
 and mark these tests as cpu multirace on Windows.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15313>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler