Created attachment 177442 [details] poudriere build log pngquant fails to configure on FreeBSD 10.3-RELEASE-p12 when building in poudriere.
The base compiler (clang) doesn't support openmp in 10.x - 11.x. If you want to use pngquant with openmp, switch to modern gcc from the ports collection or devel/llvm39.
Couldn't enabling openMP option automatically switch compiler in port configuration? Or you don't want to force specific compiler?
The OPENMP option is disabled for now.