[GHC] #10510: Testsuite driver does not run tests in parallel on Windows

[GHC]

#10510: Testsuite driver does not run tests in parallel on Windows
-------------------------------------+-------------------------------------
              Reporter:  thomie      |             Owner:
                  Type:  bug         |            Status:  new
              Priority:  high        |         Milestone:
             Component:  Test Suite  |           Version:  7.10.1
              Keywords:              |  Operating System:  Windows
          Architecture:              |   Type of failure:  None/Unknown
  Unknown/Multiple                   |        Blocked By:
             Test Case:              |   Related Tickets:
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------
 `testsuite/driver/runtests.py` contains the following 3 lines:
 {{{
 if windows:
     print("Warning: Ignoring request to use threads as running on
 Windows")
     config.use_threads = 0
 }}}

 They were introduced in commit e9b3d6cc65c0b69bd4a50bfa7bc7e1d3536446a8:
 {{{
 Author: Ian Lynagh <>
 Date:   Wed Oct 28 17:54:21 2009 +0000

     Don't use threads on Windows
     It seems to cause some sort of deadlock
 }}}

 I tried removing them (Windows 64 bit, using msys2), but then running
 validate doesn't get any further than:
 {{{
 ...
 =====> Overlap3(normal) 1605 of 4525 [2, 7, 0]
 =====> Overlap4(normal) 1606 of 4525 [2, 7, 0]
 =====> Overlap5(normal) 1607 of 4525 [2, 7, 0]
 =====> Overlap6(normal) 1608 of 4525 [2, 7, 0]
 =====> Overlap7(normal) 1609 of 4525 [2, 7, 0]
 =====> Overlap9(normal) 1610 of 4525 [2, 7, 0]
 }}}

 It would be great if we could run the testsuite in parallel again, since
 running validate takes forever currently.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10510>
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