Dependency on GNU grep had been originally added to avoid a pathological
corner case in BSD grep, where it's about two orders of magnitude slower
than GNU grep. As it occurs with one particular pattern type, it could
instead be solved by depending on pcregrep rather than gnugrep.
Submitter prefers this solution because pcregrep is already required by
other programs and does not have potential conflicts with the BSD grep
from the base.
PR: 255525, 263279
Alexey Dokuchaev
e8eb1a4a6c