On 2019-11-28 some CPPFLAGS have been added. Does the problem still persist?
The added CPPFLAGS work for me (using GCC 9.2.0). Jonathan Perkin's valuable discussion on this subject is probably already recorded in pkgsrc's archive, but just for good measure:
https://gist.github.com/jperkin/b08f9108daf8d0ac695067d71f882a9d Feel free to close this PR. Thanks to all involved. -- Jörn Clausen Plattformen & Serverdienste BITS - Bielefelder IT-Servicezentrum https://www.uni-bielefeld.de/bits