=> Bootstrap dependency digest>=20010302: found digest-20190127
=> Checksum SHA1 OK for gprolog-1.4.5.tar.gz
=> Checksum RMD160 OK for gprolog-1.4.5.tar.gz
=> Checksum SHA512 OK for gprolog-1.4.5.tar.gz
mkdir: /tmp/pkgbuild/lang/gprolog: Permission denied
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/gprolog