Not very happy about this. Such mock-config is not working in all cases. E.g. centos6 builder will incorrectly use "group install" in case it is not overriden via tag's extra. I assume it is better to have dnf-like default anyway.

Other options:
1) is to check in kojid's code /etc/mock/site-defaults.cfg and use package_manager from there. Very error-prone
2) Say that "yum" is default unless it is overriden by mock.package_manager - this would be backward-compatible, but it sets the default to something almost obsoleted/
3) Let it be and just encourage admins who still have yum-based builders/envs that they need to update mock.package_manager for all build tags that are still using it.
4) Add tag's extra setting mock.groupinstall (maybe even mock.chroot_setup_cmd template which could leverage "group_name")

@mikem ?

Hmm.

Mock itself still defaults to:

config_opts['chroot_setup_cmd'] = ('groupinstall', 'buildsys-build')

Most mock configs seem to use install @groupname. I distinctly remember this not being an option at some point, but I'm not sure how far back that was. Is it possible that we could use install @build and cover all the cases we care about (or did dnf break that too?)

A casual check suggests that this will work with yum on el6

side note: not the first time groupinstall has been a problem ;)

Historical note. Koji has used groupinstall since Nov 2007. Prior to that, it used install buildsys-build where buildsys-build was an custom generated rpm (see make_groups_spec())

+        if opts['package_manager'].endswith('yum'):
+            # backward compatibility with yum (doesn't have separate "group")
+            config_opts['chroot_setup_cmd'] = \
+                'install @%s' % opts.get('install_group', 'build')

This seems to be redundant now

I would like to allow a little time for folks to reply to my last comment on #3971

The yum-compat branch is indeed redundant.

I tested YUM on epel-5 and even that old version seems to have install @group support. I'm not able to easily test anything older than that on a reasonably new Fedora builder.

+1 for this version.

Commit d5803139 fixes this pull-request