m2e-wtp error: <path>/target/m2e-wtp/web-resources/META-INF/MANIFEST.MF (No such file or directory)

Question

I use m2e 1.2.0 and m2e-wtp 0.16.0, and occasionally my Eclipse build fails with the error:

<path>/target/m2e-wtp/web-resources/META-INF/MANIFEST.MF (No such file or directory)

The problem can be temporarily solved by doing a Maven->Update project..., but the error will come back after a while. Not sure what exactly the trigger is....

Any suggestions on how to fix the issue permanently?

[Edit] I found that the issue is triggered when I build the project externally using the Maven command line directly. This will remove the default MANIFEST.MF that m2e-wtp generates, and it apparently doesn't get regenerated until you do a rebuild in Eclipse.

Answer 1

Eclipse versions earlier than Luna

I'm not certain if this is the best thing to do but I followed the instructions mentioned here with regards to getting rid of the auto generated web resources folder and this seems to also resolve the issue with the missing MANIFEST.MF:

• on your project only : right-click on the project > Properties > Maven > WTP : check "Enable Project Specific Settings" and uncheck "Maven Archiver generates files under the build directory"
• on the whole workspace : Window > Preferences > Maven > WTP : uncheck "Maven Archiver generates files under the build directory"

We actually generate our manifest entries as part of the maven-war-plugin when we actually want to package/build the project, but I dont think m2e-wtp uses this. In any event, the manifest file is irrelevant for us in the build that m2e-wtp creates for use within eclipse.

Eclipse Luna and later

For Eclipse Luna you have to go:

Preferences > Maven > Java EE Integration and uncheck "Maven Archiver generates files under the build directory".

Eclipse Luna does not have the path at project Properties and the WTP section

Answer 2

This solution works for me Rightclick on Project --> Properties --> Maven --> Java EE Integration --> check enable project specific settings and disable Maven archiver generates files

Answer 3

Try to select your project, and clean it by using the menu :

Project>Clean

Then refresh your pom.xml. That worked for me .