the problem is either situational (e.g. the various RESTRICTED-like
cases) or unfixable in pkgsrc (no pthreads, ipv6, etc. on platform).
Conversely, if the wrong version of mysql is installed, that's a
PKG_FAIL_REASON.
automatically supply missing "basic" headers and libraries from an
older system, e.g. IRIX 5.x or Interix or AIX, etc.
Example usage:
USE_FEATURES+= snprintf glob regex
For now, we just pull in libnbcompat to supply the missing bits.
