[GHC] #15971: Hadrian fails Shake's linter on Windows

[GHC]

#15971: Hadrian fails Shake's linter on Windows
-------------------------------------+-------------------------------------
           Reporter:  bgamari        |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  high           |         Milestone:  8.8.1
          Component:  Compiler       |           Version:  8.7
           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:
-------------------------------------+-------------------------------------
 While trying to bring up a Hadrian builder on Windows I found the
 [[https://gitlab.staging.haskell.org/ghc/ghc/-/jobs/440/raw|following]];
 excerpting:
 {{{
 shakeArgsWith                        0.001s    0%
 Function shake                       0.407s    0%
 Database read                        0.001s    0%
 With database                        0.000s    0%
 Running rules                     3065.940s   99%
 =========================
 Pool finished (2932 threads, 4 max)  0.002s    0%
 Lint checking                        1.810s    0%
 Total                             3068.160s  100%
 Lint checking error - 520 values have changed since being depended upon:
   Key:  _build/stage1/gmp/objs/zero_p.o
   Old:  (Just File {mod=0x6D312A39,size=0x2EA,digest=0xACFF03E6}
 recomputed,"")
   New:  File {mod=0x7475B8F5,size=0x2EA,digest=0xACFF03E6}

   Key:  _build/stage1/gmp/objs/zero.o
   Old:  (Just File {mod=0x6DA1AAD9,size=0x2F8,digest=0x586B32DC}
 recomputed,"")
   New:  File {mod=0x74B61957,size=0x2F8,digest=0x586B32DC}

   Key:  _build/stage1/gmp/objs/xor_n.o
   Old:  (Just File {mod=0x6D9D3378,size=0x1DF,digest=0xFBB5353}
 recomputed,"")
   New:  File {mod=0x74B2AAEC,size=0x1DF,digest=0xFBB5353}
 }}}

 It looks like all of the gmp objects were somehow touched during the
 build, but their contents are unchanged. Strangely, none of these
 filenames appear elsewhere in the log, so it's unclear when they could
 have been touched.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15971>
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