email: solve install conflicts

Solve install conflicts (exim4) by removing installed conflicting packages before installation of email server.

Other likely install conflicts have been discarded: msmtp, nullmailer, sendmail. qmail and smail are less likely since they are missing in Bullseye.

Pending: (To be fixed and rebased later or even in another merge request):

• Removing conflicting packages without user notice might be too rough. A generic warning should help.
• Mock OS calls (?).

qmail and smail are not available on bullseye.

For msmtp, nullmailer and sendmail, surprinsingly enough, their mere presence doesn't break FreedomBox's Email Server installation. And they don't seem to break or block internal mailing (among FreedomBox users) either.

They might interfere if they are up running, but that's a different kind of collision that ought to be addressed differently.

The patch on top of 062763f0 is indeed unnecessary.

changed the description

Installation progress of Email Server isn't shown. Need to investigate why.

added 22 commits

• d1624e89...a8df4bcd - 20 commits from branch freedombox-team:master
• 697427c6 - package: remove packages
• 612c83b0 - email: Solve conflicts before installation.

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added 8 commits

• 612c83b0...34987c77 - 6 commits from branch freedombox-team:master
• 41cec75d - package: remove packages
• cbbfa9b1 - email: Solve conflicts before installation.

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added 3 commits

• d549a0f9 - tests: Improve handling of tests skipped by default
• f3c5eb02 - package: remove packages
• b85529c6 - email: Solve conflicts before installation.

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changed the description

marked this merge request as ready

changed the description

In the spirit of "release early, release fast" and "better done than perfect" I remove the "WIP" mark.

added 55 commits

• b85529c6...c330d7d5 - 51 commits from branch freedombox-team:master
• ce2ce6b9 - tests: Improve handling of tests skipped by default
• 9dd0e555 - package: remove packages
• 4b9ddfa6 - plinth: Solve conflicts before installation.
• fee0ec21 - email: Manage known installation conflicts

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added 6 commits

• fee0ec21...05565b1c - 2 commits from branch freedombox-team:master
• 1dfbddc9 - tests: Improve handling of tests skipped by default
• bbbe2415 - package: remove packages
• edd5ced9 - plinth: Solve conflicts before installation.
• 5577e627 - email: Manage known installation conflicts

Compare with previous version

resolved all threads

Generic warning implemented for conflicting packages installed.

Leading unknown packages in the list passed to package.py/remove() doesn't prevent removal from trailing ones anymore.