DragonFly's modern gnu grep caught use of "[:space:]" rather than
the correct "[[:space:]]" in the Gentoo ltmain sanity check, and
returned an error breaking the configure script. The m4 file was
correct though, so the configure wasn't really generated. In any
case, this Gentoo error is widespread, so expect the same patch for
other packages as they are discovered.
It's possible platforms using BSD grep aren't affected.
No PKGREVISION bump required.
This changes the buildlink3.mk files to use an include guard for the
recursive include. The use of BUILDLINK_DEPTH, BUILDLINK_DEPENDS,
BUILDLINK_PACKAGES and BUILDLINK_ORDER is handled by a single new
variable BUILDLINK_TREE. Each buildlink3.mk file adds a pair of
enter/exit marker, which can be used to reconstruct the tree and
to determine first level includes. Avoiding := for large variables
(BUILDLINK_ORDER) speeds up parse time as += has linear complexity.
The include guard reduces system time by avoiding reading files over and
over again. For complex packages this reduces both %user and %sys time to
half of the former time.
