Why doesn't Maven's mvn clean ever work the first time?

Question

Nine times out of ten when I run mvn clean on my projects I experience a build error. I have to execute mvn clean multiple times until the build error goes away. Does anyone else experience this? Is there any way to fix this within Maven? If not, how do you get around it? I wrote a bat file that deletes the target folders and that works well, but it's not practical when you are working on multiple projects. I am using Maven 2.2.1.

[ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Failed to delete directory: C:\Documents and Settings\user\My Documents\software-developm ent\a\b\c\application-domain\target. Reason: Unable to delete directory C:\Documen ts and Settings\user\My Documents\software-development\a\b\c\application-domai n\target\classes\com\a\b  [INFO] ------------------------------------------------------------------------ [INFO] For more information, run Maven with the -e switch [INFO] ------------------------------------------------------------------------ [INFO] Total time: 6 seconds [INFO] Finished at: Fri Oct 23 15:22:48 EDT 2009 [INFO] Final Memory: 11M/254M [INFO] ------------------------------------------------------------------------ 

Answer 1

It may be that your IDE or some other process is holding on to the the "target" folder and preventing maven from deleting it.

Answer 2

This is mostly caused by Windows Indexing. Excluding target folders or .jar extention from indexing will fix the problem. My best practice is excluding .jar extention.

To exclude target files:

1. Click on windows icon/start menu
2. Type indexing in search box and click on Indexing Options
3. Then click on Modify button to investigate directories indexing.
4. Remove checks of Target folders.

To excluse all .jar files:

1. Click on windows icon/start menu
2. Type indexing in search box and click on Indexing Options
3. Then click on Advanced button.
4. Go through File Types tab.
5. In the list, find jar and uncheck it.