Currently, commands like 'emerge -uD @world' will succeed (with a warning message) even though atoms from @system or @profile are unresolved.
Since @selected atoms are chosen by users, and it's common for these atoms to be unresolved for variety of reasons, it makes sense to treat unresolved atoms from @selected as a warning. It would be too much of a nuisance to do otherwise.
Anything in @system or @profile should be relatively important. Since @system and @profile atoms are presumably chosen by someone who knows what they are doing (usually a gentoo developer), it makes sense consider resolution failures for these atoms as fatal errors.
(In reply to Zac Medico from comment #0)
> Currently, commands like 'emerge -uD @world' will succeed (with a warning
> message) even though atoms from @system or @profile are unresolved.
Actually, unresolved @profile atoms are already fatal. So, @system is the only one that needs to be fixed.
I would like for it to suggest config changes, which can be written with --autounmask-write.
This is in the master branch:
Autounmask support will probably not get much use, so I'll leave that unimplemented for now.
Fixed in 2.2.27.