Log Message:
Add pkgtools/posix_headers version 0.4:
This package attempts to resolve deficiencies in system headers.
These deficiencies are commonly found on older operating system releases.
When use of posix_headers has been enabled on a platform, this package will
become a compile-time dependency for every package. It will provide customized
header files that take preference over some system provided ones (that may
not even exist). This happens transparently through use of buildlink3.