[GHC] #9619: HPC Code Coverage complains when two exactly the same mix files are on the path

[GHC]

#9619: HPC Code Coverage complains when two exactly the same mix files are on the
path
-------------------------------------+-------------------------------------
       Reporter:  Kasper             |                   Owner:
           Type:  bug                |                  Status:  new
       Priority:  lowest             |               Milestone:
      Component:  Code Coverage      |                 Version:  7.8.3
       Keywords:                     |        Operating System:  Linux
   Architecture:  x86_64 (amd64)     |         Type of failure:  Incorrect
     Difficulty:  Unknown            |  result at runtime
     Blocked By:                     |               Test Case:
Related Tickets:                     |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------
 Cabal's --enable-library-coverage flag generates the .mix files in the
 dist/mix directory that cabal creates during compilation. I have two test
 suites, integration tests and unit tests. Those test suites calll tests
 for moduleA in moduleATest. Unfortunately, in a first version, the
 integration tests and unit tests for moduleA were both present in
 moduleATest. Therefore, the unit test suite (in UnitTests.hs) and the
 integration test suite (in IntegrationTests.hs) both 'use' the moduleATest
 by linking in tests from that module. This leads to cabal generating a
 directory integration-tests and a directory unit-tests with .mix files,
 but the moduleATest.mix file is present in both directories. When
 performing hpc sum and hpc markup to get the total result of the test runs
 I need to specify the directories where the mix files are present (so
 dist/hpc/mix/unit-tests and dist/hpc/mix/integration-tests) and it will
 then complain that it finds moduleATest.mix file twice.


 This issue is not present when using the -fhpc flag, as the directory
 structure with integration-tests and unit-tests is not present in the .hpc
 directory at that moment. That being said, I don't think it's a cabal
 issue as it's more or less expected what they're doing, generating the mix
 files necessary to instrument integration-tests and unit-tests separately.

 Priority put to lowest because I can work around it by diving moduleATest
 up in moduleATest and moduleAIntegrationTest, which is saner in the end
 anyway. But I guess somebody will come up with a use case where a split up
 isn't possible, in the future.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9619>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler