Merge pull request #5757 from zyla/random-test-ghc-env

Randomize `test-ghc-env` to avoid conflicts between parallel jobs

Author: mpilgrem

ChangeLog.md

@@ -58,6 +58,9 @@ Bug fixes:
   [5792](https://github.com/commercialhaskell/stack/issues/5792).
 * Fixed output of `stack ls snapshots local` on Windows, to behave like that on
   Unix-like operating systems.
+* Fix non-deterministic test failures when executing a test suite for a
+  multi-project repository with parallelism enabled. See
+  [#5024](https://github.com/commercialhaskell/stack/issues/5024)
 
 ## v2.7.5
 

package.yaml

@@ -110,6 +110,7 @@ dependencies:
 - primitive
 - process >= 1.6.13.2
 - project-template
+- random
 - retry
 - rio >= 0.1.22.0
 - rio-prettyprint >= 0.1.1.0

src/Stack/Build/Execute.hs

@@ -95,6 +95,7 @@ import           System.PosixCompat.Files (createLink, modificationTime, getFile
 import           RIO.PrettyPrint
 import           RIO.Process
 import           Pantry.Internal.Companion
+import           System.Random (randomIO)
 
 -- | Has an executable been built or not?
 data ExecutableBuildStatus
@@ -1930,8 +1931,13 @@ singleTest topts testsToRun ac ee task installedMap = do
                 let setEnv f pc = modifyEnvVars pc $ \envVars ->
                       Map.insert "HASKELL_DIST_DIR" (T.pack $ toFilePath buildDir) $
                       Map.insert "GHC_ENVIRONMENT" (T.pack f) envVars
-                    fp = toFilePath $ eeTempDir ee </> testGhcEnvRelFile
-                    snapDBPath = toFilePathNoTrailingSep (bcoSnapDB $ eeBaseConfigOpts ee)
+                    fp' = eeTempDir ee </> testGhcEnvRelFile
+                -- Add a random suffix to avoid conflicts between parallel jobs
+                -- See https://github.com/commercialhaskell/stack/issues/5024
+                randomInt <- liftIO (randomIO :: IO Int)
+                let randomSuffix = "." <> show (abs randomInt)
+                fp <- toFilePath <$> addExtension randomSuffix fp'
+                let snapDBPath = toFilePathNoTrailingSep (bcoSnapDB $ eeBaseConfigOpts ee)
                     localDBPath = toFilePathNoTrailingSep (bcoLocalDB $ eeBaseConfigOpts ee)
                     ghcEnv =
                         "clear-package-db\n" <>

stack.cabal

@@ -286,6 +286,7 @@ library
     , primitive
     , process >=1.6.13.2
     , project-template
+    , random
     , retry
     , rio >=0.1.22.0
     , rio-prettyprint >=0.1.1.0
@@ -409,6 +410,7 @@ executable stack
     , primitive
     , process >=1.6.13.2
     , project-template
+    , random
     , retry
     , rio >=0.1.22.0
     , rio-prettyprint >=0.1.1.0
@@ -533,6 +535,7 @@ executable stack-integration-test
     , primitive
     , process >=1.6.13.2
     , project-template
+    , random
     , retry
     , rio >=0.1.22.0
     , rio-prettyprint >=0.1.1.0
@@ -662,6 +665,7 @@ test-suite stack-test
     , primitive
     , process >=1.6.13.2
     , project-template
+    , random
     , raw-strings-qq
     , retry
     , rio >=0.1.22.0