CommentPicklingTest fails on Windows

[melekhove]

Seen in testOnly dotty.tools.vulpix.VulpixUnitTests

[allanrenucci]

Could you post a stack trace?

[melekhove]

It could be that my path in #5150 is wrong. At least according to the following stack trace.
But I'm sure that I saw exception at line 211.

Strange.

Here is the stack trace:

[info] Test dotty.tools.dotc.core.tasty.CommentPicklingTest.commentOnClass started
[error] Test dotty.tools.dotc.core.tasty.CommentPicklingTest.commentOnClass failed: java.nio.file.DirectoryNotEmptyException: C:\Users\mev\AppData\Local\Temp\temp7046534152377005690\out, took 0.306 sec
[error]     at sun.nio.fs.WindowsFileSystemProvider.implDelete(WindowsFileSystemProvider.java:266)
[error]     at sun.nio.fs.AbstractFileSystemProvider.delete(AbstractFileSystemProvider.java:103)
[error]     at java.nio.file.Files.delete(Files.java:1126)
[error]     at dotty.tools.io.Path$$anon$1.postVisitDirectory(Path.scala:216)
[error]     at dotty.tools.io.Path$$anon$1.postVisitDirectory(Path.scala:209)
[error]     at java.nio.file.Files.walkFileTree(Files.java:2688)
[error]     at java.nio.file.Files.walkFileTree(Files.java:2742)
[error]     at dotty.tools.io.Path.deleteRecursively(Path.scala:209)
[error]     at dotty.tools.io.Directory$.inTempDirectory(Directory.scala:29)
[error]     at dotty.tools.dotc.core.tasty.CommentPicklingTest.compileAndUnpickle(CommentPicklingTest.scala:82)
[error]     at dotty.tools.dotc.core.tasty.CommentPicklingTest.compileAndCheckComment(CommentPicklingTest.scala:61)
[error]     at dotty.tools.dotc.core.tasty.CommentPicklingTest.commentOnClass(CommentPicklingTest.scala:47)

[melekhove]

Update to the issue. I've changed the title because problem is not in the dotty.tools.io.Path but somewhere else.

Here is a stack trace

sbt:dotty> testOnly dotty.tools.dotc.core.tasty.CommentPicklingTest -- *commentOnDef
[info] Test dotty.tools.dotc.core.tasty.CommentPicklingTest.commentOnDef started
[error] Test dotty.tools.dotc.core.tasty.CommentPicklingTest.commentOnDef failed: java.nio.file.DirectoryNotEmptyExcepti
on: C:\Users\mev\AppData\Local\Temp\temp7552947933988336858\out, took 2.665 sec
[error]     at sun.nio.fs.WindowsFileSystemProvider.implDelete(WindowsFileSystemProvider.java:266)
[error]     at sun.nio.fs.AbstractFileSystemProvider.delete(AbstractFileSystemProvider.java:103)
[error]     at java.nio.file.Files.delete(Files.java:1126)
[error]     at dotty.tools.io.Path$$anon$1.postVisitDirectory(Path.scala:216)
[error]     at dotty.tools.io.Path$$anon$1.postVisitDirectory(Path.scala:209)
[error]     at java.nio.file.Files.walkFileTree(Files.java:2688)
[error]     at java.nio.file.Files.walkFileTree(Files.java:2742)
[error]     at dotty.tools.io.Path.deleteRecursively(Path.scala:209)
[error]     at dotty.tools.io.Directory$.inTempDirectory(Directory.scala:29)
[error]     at dotty.tools.dotc.core.tasty.CommentPicklingTest.compileAndUnpickle(CommentPicklingTest.scala:82)
[error]     at dotty.tools.dotc.core.tasty.CommentPicklingTest.compileAndCheckComment(CommentPicklingTest.scala:61)
[error]     at dotty.tools.dotc.core.tasty.CommentPicklingTest.commentOnDef(CommentPicklingTest.scala:27)
[error]     ...
[info] Test run finished: 1 failed, 0 ignored, 1 total, 3.014s
[error] Failed: Total 1, Failed 1, Errors 0, Passed 0
[error] Failed tests:
[error]         dotty.tools.dotc.core.tasty.CommentPicklingTest
[info] Passed: Total 0, Failed 0, Errors 0, Passed 0
[info] No tests to run for dotty-doc / Test / testOnly
[error] (dotty-compiler / Test / testOnly) sbt.TestsFailedException: Tests unsuccessful
[error] Total time: 6 s, completed 26.09.2018 11:52:42

Test fails attempting to delete 'out' directory which is actually empty (files are deleted prior to the call to
postVisitDirectory) There are no any hidden files etc.

The interesting thing is that if we comment out 'unpickle' call the test passes

diff --git a/compiler/test/dotty/tools/dotc/core/tasty/CommentPicklingTest.scala b/compiler/test/dotty/tools/dotc/core/tasty/CommentPicklingTest.scala
index 4cafc167302..06e65884bd0 100644
--- a/compiler/test/dotty/tools/dotc/core/tasty/CommentPicklingTest.scala
+++ b/compiler/test/dotty/tools/dotc/core/tasty/CommentPicklingTest.scala
@@ -100,7 +100,7 @@ class CommentPicklingTest {
         .withClasspath(out.toAbsolute.toString)
         .and("dummy") // Need to pass a dummy source file name
       val unpicklingDriver = new UnpicklingDriver
-      unpicklingDriver.unpickle(unpicklingOptions.all, tastyFiles)(fn)
+//      unpicklingDriver.unpickle(unpicklingOptions.all, tastyFiles)(fn)
     }
   }

Scala sources compilation performed before this step doesn't affect the test. So there is some interesting difference between Driver and UnpicklingDriver which results in some kind of locking the 'out' directory

[melekhove]

Ok, I finally managed to find the real reason which fortunately has nothing to do with compiler internals and was in test implementation. Details are in #5170