pkgtools/libnbcompat provides a number of "compatibility" header files
for systems that do not come with these, such as fnmatch.h or regex.h.
They are in the include/nbcompat subdirectory, so they are not
automatically found even if ../../pkgtools/libnbcompat/buildlink3.mk is
included.
Adding the respective .buildlink/include/nbcompat path to the list of
include path holds the disadvantage of all files being found, and some
might not be desired over the ones supplied natively by the system.
One solution is to patch the code, e.g. to include nbcompat/regex.h
instead of regex.h, as does e.g. devel/bmake's patch-aa.
This is of course quite cumbersome, and it requires every respective
package to decide again whether to use a native header file or not.
A better approach IMHO is to have respective relative symlinks in
${PREFIX}/include pointing to the respective header files in the
nbcompat subdirectory. Of course it should be made sure that they are
included in the PLIST files so buildlink automatically copies them.

Comments would be appreciated :-)


-- 
Georg Schwarz    http://home.pages.de/~schwarz/
 georg.schwarz@freenet.de  +49 178 8545053