RawDBReaderTest fails on Windows

.<assertDirectoryDeleted> attempt 1 left 2 files/dirs behind: 0=extinout\recovery.sql 1=extinout
<assertDirectoryDeleted> attempt 2 left 2 files/dirs behind: 0=extinout\recovery.sql 1=extinout
<assertDirectoryDeleted> attempt 3 left 2 files/dirs behind: 0=extinout\recovery.sql 1=extinout
<assertDirectoryDeleted> attempt 4 left 2 files/dirs behind: 0=extinout\recovery.sql 1=extinout
F
Time: 39,498
There was 1 failure:
1) RawDBReaderTest:embeddedjunit.framework.AssertionFailedError: Failed to delete 2 files (root=C:\cygwin64\tmp\derbytst\extinout): C:\cygwin64\tmp\derbytst\extinout\recovery.sql (isDir=false, canRead=true, canWrite=true, size=801), C:\cygwin64\tmp\derbytst\extinout (isDir=true, canRead=true, canWrite=true, size=0)
        at org.apache.derbyTesting.junit.BaseTestCase.assertDirectoryDeleted(BaseTestCase.java:1125)
        at org.apache.derbyTesting.junit.DropDatabaseSetup.removeDirectory(DropDatabaseSetup.java:128)
        at org.apache.derbyTesting.junit.DropDatabaseSetup.removeDirectory(DropDatabaseSetup.java:118)
        at org.apache.derbyTesting.junit.SupportFilesSetup.tearDown(SupportFilesSetup.java:130)
        at junit.extensions.TestSetup$1.protect(TestSetup.java:24)
        at junit.extensions.TestSetup.run(TestSetup.java:27)

FAILURES!!!
Tests run: 1,  Failures: 1,  Errors: 0