Bean already exists: "weblogic.j2ee.descriptor.wl.JDBCPropertyBeanImpl JDBCDriverParams/Properties/Properties[user])

I was getting this error while committing changes on a DataSource:

Bean already exists: "weblogic.j2ee.descriptor.wl.JDBCPropertyBeanImpl JDBCDriverParams/Properties
/Properties[user])

Deleting the DataSource didn't help.

I tried editing manually config.xml, and I discovered that there was a swap file for vi to recover. I deleted it:

mv .config.xml.swp config.xml.swpORI

Then I discovered that in the config/jdbc folder there was still a xml file with the preexisting DataSource, although I had deleted it. So I removed it:

rm jdbc/AcmeDataSourceUS-0327-jdbc.xml

At this point I managed to recreate the DataSource.

Wow. What a fight.