User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:69.0) Gecko/20100101 Firefox/69.0

Steps to reproduce:

Load attached webextension in about:debugging, try to debug it.

Actual results:

Source code is nowhere to be found.

Expected results:

Source code should have been available.

This happens on both FF69 and FF71 and maybe on versions in between, although I didn't bother to check.

I can see the content.js file in the Toolbox (see the attached screenshot)

But, I can't see the other files coming from the extension.
(e.g. background.js)

Jason, are those supposed to be accessible in the Sources panel?

Honza

Background files are supposed to be available in the "background console" (the one you open through about:debugging). Here's a screenshot showing an empty background debugger even though the background script did execute (things are logged in the console).

I can still reproduce the problem, my STRs.

1. Load the attached extension using about:debugging (Load temporary extension)
2. Click the Inspect button next to the extension entry (in about:debugging)
3. Check out the (Tab) Toolbox, there are no sources in the Sources tree and there should be at least the content.js source
   (see also the screenshot in comment #2)

You can use the regular Toolbox:

1. Keep the extension installed
2. Load google.com
3. Select the Debugger panel
4. Expand the reproducer entry in the Sources tree
5. The content.js file available

BP in the file works as expected.

Chrome also shows just the content.js file since it's the one associated with the current page.

Honza