On Gentoo, how do I rebuild all packages depended on some other package?

Question

I made mistake and changed perl non-threaded version to threaded by unmerge first, change USE flags to include ithreads and emerge perl again. Now most packages depending on perl are broken. How do I rebuild them?

Answer 1

On way is to use equery's depends function to get the list of things that depend on a package.

# equery depends perl

If you want to rebuild all of them, try something like:

# emerge -a --oneshot `equery depends perl|awk '{print " ="$1}'`

You'll have issues with that if you have packages installed that were removed from the portage tree, so a sync and world update beforehand is a good idea.

For this specific case, you might also want to look at app-admin/perl-cleaner - it has specific features to rebuild perl modules.

Answer 2

Try using revdep-rebuild (from app-portage/gentoolkit package, same as equery). It is a tool that scans the system for broken dependencies (like missing shared libraries) and rebuilds the packages that have broken dependencies. An advantage of this compared to Mat's method is that in most cases you don't need to rebuild all packages that depend upon some other one.