USE dependencies and IUSE defaults interact in a strange way, as the following session illustrates. Copy attached foo-1.ebuild and baz-1.ebuild into an overlay (app-misc category) and install them: # USE="-quux" emerge -1 app-misc/baz # emerge app-misc/foo [These should succeed] Now let's do an unchanged version bump, copy baz-1.ebuild to baz-2.ebuild. Try to update foo and its dependencies: # emerge -uDN app-misc/foo Calculating dependencies... done! >>> Auto-cleaning packages... >>> No outdated packages were found on your system. [Huh? No update for baz? But foo depends on baz, and I requested "-D".] [Let's try an explicit update then:] # emerge -uDN app-misc/foo app-misc/baz Calculating dependencies... done! >>> Recording app-misc/baz in "world" favorites file... >>> Auto-cleaning packages... >>> No outdated packages were found on your system. [Still no update? Try the same command again, but with "-p" ...] # emerge -uDNp app-misc/foo app-misc/baz These are the packages that would be merged, in order: Calculating dependencies... done! !!! One or more updates have been skipped due to a dependency conflict: app-misc/baz:0 ('ebuild', '/', 'app-misc/baz-2', 'merge') conflicts with app-misc/baz[-quux] required by ('installed', '/', 'app-misc/foo-1', 'nomerge') Why is there a conflict? foo requires baz[-quux] and the installed baz-1 also has USE="-quux". Shouldn't it just update baz with the same flags?
Created attachment 204783 [details] app-misc/foo/foo-1.ebuild
Created attachment 204785 [details] app-misc/baz/baz-1.ebuild
Forgot to mention, the above is with portage-2.2_rc40.
This is very similar to bug 284934, but it involves a different backtracking case.
> Shouldn't it just update baz with the same flags? No, your configuration says otherwise. Assume you don't have any package installed after the version bump, then "emerge baz" would install baz-2 with USE="quux". That's basically why specifying USE on the command line is a bad idea. Running USE="-quux" emerge -uDN app-misc/foo would have done what you are after. Another thing is the confusion created by the backtracking. I have a patch ready that stops emerge from backtracking if --update is given and the use configuration doesn't match [1]. [1] http://github.com/few/fews-portage-branch/tree/dont_miss_updates_because_of_invalid_use_config
