The ability of upgrading one packagename with another would shrink the timeframe where a system cannot be used. For example if you have XFree
installed and update to Xorg, you have to unmerge XFree first because it
blocks. Depending on the power of the machine, this can mean 2-3h without X.
All those problems could be avoided if emerge would let you upgrade from XFree
directly to Xorg. The same way as you usualy upgrade an app from version 1.0
Steps to Reproduce:
The big question is which kind of syntax could be used for this.
If the portage-devs have no perfect solution for the syntax, maybe the
a request for suggestions should be sent to the dev-mailinglist.
Something like slackware uses would be:
emerge -u x11-base/xfree%x11-base/xorg
(a % as seperator)
Having something in the ebuild which describes the "next hop" isn't really
usable because except for updates like XFree->Xorg the "new appname" cannot
be guessed (Like when updating from Sendmail to Exim for example).
*** This bug has been marked as a duplicate of 79606 ***