I was just getting started with Cargo and was really frustrated that Cargo seemed to deploy my application as ".war" no matter what I tried. Unfortunately in Tomcat this name seems to be not allowed. After downloading the Cargo source-code and debugging the code, I could find that if the war contains a META-INF/context.xml you can configure whatever you want, it will allways be ignored.
In my case I configured the context to have a path of "/" which resulted in the illegal war-name.
It would be great if the plugin would use the context configured in maven, because propably the user had a reason for configuring it that way. If it is ignored, a message would be great. I would suggest to have this priority-ranks:
1. If its explicitly configured in the pom, use that context-name
2. If no context name is configured, check in the war, if it contains a context.xml with and use that data
3. Use the default file name as context.
Looking forward to actually start using this plugin now that I sorted this out