mvn clean failure hold by windows process - windows

Question

How to know which windows processes are holding the folders while doing "mvn clean" results in failure ?
I suspect some unknown process are holding my "target" folder, which is stopping me to proceed further
Is there any way to find that unknown process ?
[DEBUG] Configuring mojo org.apache.maven.plugins:maven-clean-plugin:2.5:clean from plugin realm ClassRealm[plugin>org.apache.maven.plugins:maven-clean-plugin:2.5, parent: sun.misc.Launcher$AppClassLoader#2d4b1fda]
[DEBUG] Configuring mojo 'org.apache.maven.plugins:maven-clean-plugin:2.5:clean' with basic configurator -->
[DEBUG] (f) directory = C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target
[DEBUG] (f) excludeDefaultDirectories = false
[DEBUG] (f) failOnError = true
[DEBUG] (f) followSymLinks = false
[DEBUG] (f) outputDirectory = C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target\classes
[DEBUG] (f) reportDirectory = C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target\site
[DEBUG] (f) retryOnError = true
[DEBUG] (f) skip = false
[DEBUG] (f) testOutputDirectory = C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target\test-classes
[DEBUG] -- end configuration --
[INFO] Deleting C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target
[INFO] Deleting directory C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 26.290 s
[INFO] Finished at: 2017-08-21T15:16:16+05:30
[INFO] Final Memory: 14M/124M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-clean-plugin:2.5:clean (default-clean) on project quality-manager: Failed to clean project: Failed to delete C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-clean-plugin:2.5:clean (default-clean) on project quality-manager: Failed to clean project: Failed to delete C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:216)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:120)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:347)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:154)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:582)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:214)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:158)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoExecutionException: Failed to clean project: Failed to delete C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target
at org.apache.maven.plugin.clean.CleanMojo.execute(CleanMojo.java:215)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:132)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
... 19 more
Caused by: java.io.IOException: Failed to delete C:\RafiWork\TASK\French\Sprint2\pdm_sonartool\quality-manager\target
at org.apache.maven.plugin.clean.Cleaner.delete(Cleaner.java:249)
at org.apache.maven.plugin.clean.Cleaner.delete(Cleaner.java:191)
at org.apache.maven.plugin.clean.Cleaner.delete(Cleaner.java:117)
at org.apache.maven.plugin.clean.CleanMojo.execute(CleanMojo.java:193)

Answer 1

I tend to get this when I've left a debugger running or the project running on a local webserver. Sometimes it can go a bit funny and hang around even when you think you've stopped it.
When that happens I usually tend to just go to task manager and kill any java processes running on my machine and it usually fixes it.

Answer 2

Use Handle, from Mark Russinovitch, Sysinternals (now Microsoft):
https://learn.microsoft.com/en-us/sysinternals/downloads/handle
This will help you find the offender (it's often your own Java process, or Explorer.exe, or even your CMD.EXE from where you're running Maven).