Detect conflict with extrepo

[wknapik]

# apt update
E: Conflicting values set for option Signed-By regarding source https://brave-browser-apt-release.s3.brave.com/ stable: /usr/share/keyrings/brave-browser-archive-keyring.gpg != /var/lib/extrepo/keys/brave_release.asc
E: The list of sources could not be read.
#

[fmarier]

I suppose we could install using extrepo in that case?

[wknapik]

We could detect if extrepo is installed and if our repo is added via extrepo. If it is, then just install the browser. If it isn't, we could either use extrepo to add our repo, or install our own config. Using extrepo would prevent future breakage if the user adds the brave repo via extrepo, but it might not be the user's preference to use extrepo for brave (they might have it installed, but unused).

We could also look for any pre-existing repo definitions for brave, not just extrepo's, and do something if we find them, since they could all cause problems.

[fmarier]

I installed extrepo (without enabling the brave_release repository) and there's no conflict when I run apt update.

There are only conflicts when I have extrepo installed and I run extrepo enable brave_release. That's not something we need to support since it's not a recommended way to install Brave.

What I suggest we do is simply look for the presence of /etc/apt/sources.list.d/extrepo_brave_release.sources (unless it contains Enabled: no) and then error out:

Detected the presence of a conflicting extrepo repository. Disable with extrepo disable brave_release and try again.