Since there can be multiple tags, the check must be done once for all of
them at the same time. Otherwise any module found only in some and not
all tags would raise this error.
The code builds a set of all existing patterns and then removes items
from it. If there is something left once all tags are processed, it
means such patterns were not matched by anything.
JIRA: COMPOSE-3609
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>
e68e17d8fe