During development release running devel
is fine.
Enabling devel-proposed
is not supported at all, as devel-proposed
during release development is not meant for human consumption.
It contains knowingly broken packages that are in progress being fixed and are held back from migrating to devel
because they are broken, uninstallable, contain critical bugs, and some may never be released.
Please disable devel-proposed
on your system, and please downgrade all packages to versions from devel
.
Alternatively you may wish to contribute fixes to upgrade things in devel-proposed
. See ProposedMigration - Ubuntu Wiki for more details of all the things that must be fixed for things to mgirate.