Eclipse hangs while opening workspace after upgrading to GWT 2.0/Google app engine 1.2.8

Question

After upgrading to the newest GWT/Google app engine I have problems opening my workspace in Eclipse. On startup, Eclipse hangs almost immediately and needs to be closed. This happens only in the workspace where I use GWT with app engine, and I weren't able to consistently reproduce it - sometimes it starts normally, and sometimes I need to kill the proces and restart it. There is nothing in Eclipse error log. Eclipse version is Galileo, running on Windows 7 RC.

Anyone else had similar problems? I googled but Google is not my friend today.

EDIT: Still happens after upgrading to GWT 2.0.1.

Answer 1

I got frustrated with not being able to open my workspace today, and finally solved this by importing projects into a new clean workspace.

1. Create new workspace and open it in Eclipse (to create .metadata folder).
2. Close Eclipse.
3. Manually copy all settings from old workspace (the most important settings are stored in the .metadata/.plugins/org.eclipse.core.runtime/.settings directory). Alternatively, you could use File / Export / General / Preferences in Eclipse, and then File / Import them, but I wasn't able to open workspace to do that.
4. Open the new workspace.
5. File / Import / General / Existing projects into workspace. Select root folder of your old workspace, and take care to check "Copy project into workspace".
6. Restart Eclipse and check that everything in the new workspace is working as it should.
7. Delete your old workspace.

EDIT: Another, and a bit better workaround which apparently works:

1. Close Eclipse.
2. Temporary move offending project somewhere out of the workspace.
3. Start Eclipse, wait for workspace to load (it should).
4. Close Eclipse again.
5. Move the project back to workspace.

Answer 2

I just deleted the state.dat file in the GWT project metadata, which seemed to remove the blocking and then triggered a recompilation.

<workspace>/.metadata/.plugins/org.eclipse.core.resources/.projects/<GWT project>/org.eclipse.jdt.core/state.dat

This probably won't serve as a general solution, but it worked for me and it's a lot quicker than having to copy whole projects. Maybe another file will have the same effect. I think the trick is just to "damage" the GWT project metadata enough to have it rebuilt.

Answer 3

I used "eclipse -refresh". Apparently it hangs on refresh something, the lower right corner tells you, what it's doing. For me it was refreshing the gwt runtime in a specific project, maybe trying to find an update or something. If you don't want to reimport your whole workspace, try -refresh or move this project temporarily out of the way.