Remove coursier cache from slug

[jkutner]

Coursier leaves a large .sbt_home/.cache/coursier/ directory in the slug. I'm not sure what it's job is, but it can probably be removed from the slug and kept in the build cache.

[drobert]

We ran into the same thing. Seems to be a quick fix, I can try to put a PR up tonight, but:

heroku-buildpack-scala/bin/compile

Lines 177 to 180 in f9e6ab2

	if [ "$KEEP_COURSIER_CACHE" != "true" ] && [ -d $SBT_USER_HOME/.coursier ]; then
	status "Dropping coursier cache from the slug"
	rm -rf $SBT_USER_HOME/.coursier
	fi

looks for a directory .coursier but the directory name, as noted, is .cache

[drobert]

PR available: #148

[drobert]

Incidentally, as a temporary workaround, we've done this in build.sbt:

  .settings(
    // ...
    stageCleanupTask := {
      val localStage = (stage in Universal).value
      val log = streams.value.log
      if (sys.env.getOrElse("POST_STAGE_CLEAN", "true").equals("true")) {
        def cleanup(base: File): PathFinder = {
          // build artifacts typically within a "target" dir, but even
          // the root's aren't needed
          base ** "target" * ("scala-2.12" || "streams") +++
          // any 'target' directory that isn't the root project's
          ((base ** "target") --- (base / "target")) +++
          // ivy2 or coursier lib caches
          base ** (".ivy2" || ".cache")
        }
        sbt.IO.delete(cleanup(baseDirectory.value).get)
      }
      localStage
    },
    stage := stageCleanupTask.value,
    // ...

[Malax]

This seems to be fixed since 18da922, closing.