Contents

Content scripts don't appear in DevTools

Description: Content scripts sometimes don't appear in the sources list when debugging a tab on Android.

Workaround: Add adebugger statement to your content script to manually trigger a breakpoint when the content script first executes.

Extension source don't update in DevTools

Description: Sources files open in DevTools are not updated after you edit the file on disk. This issue applies to temporary extensions installed in Firefox or on an Android device usingweb-ext.

Workaround: Close and re-open DevTools.

"Destroyed actor" errors when debugging Android

Description: While debugging an extension on Android, you may encounter an error in Firefox on your desktop that says something like:

Cannot connect to the debug target. See error details below:

Error: Protocol error (Error): Attempted to write a response containing a destroyed actor from: root (resource://devtools/shared/protocol/types.js:358:17)

Workaround: In theabout:debugging page on your development computer, disconnect from and reconnect to the Android device.

Additional notes: This issue appears to be related to simultaneous connections to the Android device fromweb-ext and Firefox's developer tools. To minimize the likelihood of this issue, setweb-ext to auto-reload specific files only using the--watch-files flag. For example:

web-ext run-t firefox-android\  --android-device=emulator-5554\  --firefox-apk=org.mozilla.fenix\  --watch-file manifest.json

This approach also allows you to manually trigger a refresh by pressingR while the web-ext terminal window is focused.