Debugging Firefox Extensions

Well today I learned how to debug extensions in librewolf with about:debugging#/runtime/this-firefox

I use a self hosted Vaultwarden instance for password management and the bitwarden extension I use in Librewolf was giving me "unknown error" when I tried to sign in. I figured there had to be a way to get at what the actual error was, so with a little digging I found the above about:debugging string above. In that debug screen there's a list of extensions you have installed, and clicking on "Inspect" brings up the familiar web inspection tools scoped to just your extension. Once in there, I brought up the console tab and tried my login again. Sure enough there's a 404 error trying to reach the password URL. It turns out there was a change to that path in a recent update in bitwarden/vaultwarden and the version of the vaultwarden I was running was a bit behind. I pulled down the new version, restarted my VW container and VIOLIN! I was able to login again.

It was a minor thing, but I'm just glad I was able to find that. Hopefully this post can be useful to someone (maybe even future me, lol) curious on where to find real error messages in a firefox extension.