bazel: Windows: rebuild and clean sometimes fail with DirectoryNotEmptyException

When I use Bazel 0.15.2 to rebuild Bazel I got this error sometimes:

ERROR: C:/tools/msys64/home/pcloudy/workspace/bazel/src/main/java/com/google/devtools/build/skyframe/BUILD:25:1: Building src/main/java/com/google/devtools/build/skyframe/libskyframe.jar (72 source files) and running annotation processors (AutoCodecProcessor, OptionProcessor) failed (Exit 1): java.exe failed: error executing command
  cd C:/users/pcloudy/_bazel_pcloudy/3uxo2r6v/execroot/io_bazel
  SET LC_CTYPE=en_US.UTF-8
  external/embedded_jdk/bin/java.exe -Xbootclasspath/p:external/bazel_tools/third_party/java/jdk/langtools/javac-9+181-r4173-1.jar -jar external/bazel_tools/tools/jdk/JavaBuilder_deploy.jar @bazel-out/x64_windows-fastbuild/bin/src/main/java/com/google/devtools/build/skyframe/libskyframe.jar-2.params
java.io.IOException: Cannot clean 'bazel-out\x64_windows-fastbuild\bin\src\main\java\com\google\devtools\build\skyframe\_javac\skyframe\libskyframe_classes'
        at com.google.devtools.build.buildjar.SimpleJavaLibraryBuilder.cleanupDirectory(SimpleJavaLibraryBuilder.java:91)
        at com.google.devtools.build.buildjar.SimpleJavaLibraryBuilder.prepareSourceCompilation(SimpleJavaLibraryBuilder.java:53)
        at com.google.devtools.build.buildjar.SimpleJavaLibraryBuilder.compileJavaLibrary(SimpleJavaLibraryBuilder.java:113)
        at com.google.devtools.build.buildjar.SimpleJavaLibraryBuilder.run(SimpleJavaLibraryBuilder.java:132)
        at com.google.devtools.build.buildjar.BazelJavaBuilder.processRequest(BazelJavaBuilder.java:105)
        at com.google.devtools.build.buildjar.BazelJavaBuilder.runPersistentWorker(BazelJavaBuilder.java:67)
        at com.google.devtools.build.buildjar.BazelJavaBuilder.main(BazelJavaBuilder.java:45)
Caused by: java.nio.file.DirectoryNotEmptyException: bazel-out\x64_windows-fastbuild\bin\src\main\java\com\google\devtools\build\skyframe\_javac\skyframe\libskyframe_classes\com\google\devtools\build
        at sun.nio.fs.WindowsFileSystemProvider.implDelete(WindowsFileSystemProvider.java:266)
        at sun.nio.fs.AbstractFileSystemProvider.delete(AbstractFileSystemProvider.java:103)
        at java.nio.file.Files.delete(Files.java:1126)
        at com.google.devtools.build.buildjar.SimpleJavaLibraryBuilder$1.postVisitDirectory(SimpleJavaLibraryBuilder.java:85)
        at com.google.devtools.build.buildjar.SimpleJavaLibraryBuilder$1.postVisitDirectory(SimpleJavaLibraryBuilder.java:73)
        at java.nio.file.Files.walkFileTree(Files.java:2688)
        at java.nio.file.Files.walkFileTree(Files.java:2742)
        at com.google.devtools.build.buildjar.SimpleJavaLibraryBuilder.cleanupDirectory(SimpleJavaLibraryBuilder.java:71)
        ... 6 more
Target //src:bazel failed to build
INFO: Elapsed time: 36.284s, Critical Path: 14.20s
INFO: 44 processes: 23 local, 21 worker.
FAILED: Build did NOT complete successfully

pcloudy@pcloudy0-w MSYS ~/workspace/bazel
$ bazel clean
Starting local Bazel server and connecting to it...
INFO: Starting clean.
ERROR: C:/users/pcloudy/_bazel_pcloudy/3uxo2r6v/execroot/io_bazel/bazel-out/x64_windows-fastbuild/bin/src/main/java/com/google/devtools/build/lib/remote/blobstore/_javac/blobstore/libblobstore_classes/com/google (Directory not empty)

pcloudy@pcloudy0-w MSYS ~/workspace/bazel
$ ls /c/users/pcloudy/_bazel_pcloudy/3uxo2r6v/execroot/io_bazel/bazel-out/x64_windows-fastbuild/bin/src/main/java/com/google/devtools/build/lib/remote/blobstore/_javac/blobstore/libblobstore_classes/com/google

pcloudy@pcloudy0-w MSYS ~/workspace/bazel
$ bazel clean
INFO: Starting clean.
ERROR: C:/users/pcloudy/_bazel_pcloudy/3uxo2r6v/execroot/io_bazel/bazel-out/x64_windows-fastbuild (Directory not empty)

pcloudy@pcloudy0-w MSYS ~/workspace/bazel
$ bazel clean
INFO: Starting clean.

FYI @laszlocsomor