[GHC] #15022: Stackage HEAD detected a suspicious change

[GHC]

#15022: Stackage HEAD detected a suspicious change
-------------------------------------+-------------------------------------
        Reporter:  mrkkrp            |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.2.2
      Resolution:  invalid           |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by mrkkrp):

 * status:  new => closed
 * resolution:   => invalid


Comment:

 It looks like this was a false alarm. I re-run the script with the older
 GHC bindist and got single test suite run. Something has changed but the
 change is not caused by GHC.

 So, one test suite (test-threaded) is not run anymore for unknown reason.
 The other test suite (test) is run. They are almost identical BTW:

 {{{
 test-suite test
     type: exitcode-stdio-1.0

     hs-source-dirs: test
     main-is: Main.hs

     ghc-options: -Wall
                  -fno-warn-missing-signatures
                  -fno-warn-name-shadowing
                  -fno-warn-unused-do-bind
                  -fno-warn-unused-matches

     build-depends: base >= 4.3 && < 5
                  , stm
                  , stm-delay

 test-suite test-threaded
     type: exitcode-stdio-1.0

     hs-source-dirs: test
     main-is: Main.hs

     ghc-options: -Wall -threaded
                  -fno-warn-missing-signatures
                  -fno-warn-name-shadowing
                  -fno-warn-unused-do-bind
                  -fno-warn-unused-matches

     build-depends: base >= 4.3 && < 5
                  , stm
                  , stm-delay
 }}}

 There was also a bug in detection of failing packages (those that failing
 not during building but during configuration step were not included in the
 report at all), there 27 failing packages, but this is not relevant in
 this case.

 I have adjusted the setup to exclude any changes but those introduced by
 GHC:
 * We previously downloaded `stack` in binary form on every run without
 controlling whether it's the same `stack` every time. `stack` binary is
 now fixed and cannot change between runs.
 * The same for `stackage-curator`.
 * The docker image we used `snoyberg/stackage:nightly` also changes
 frequently and so I created a different image that I won't update unless
 needed.
 * We previously run `stack update` on every execution of the script, which
 may have affected the results. I included this command in `Dockerfile`
 instead so updates of Hackage indices are controlled as well.

 This should eliminate influence of external factors on results that we
 observe.

 So, again, sorry for the false alarm!

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15022#comment:14>
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