Created attachment 167313 [details] synth build log It appears that nghttp2 is incompatible with the version of OpenSSL currently in ports and is instead linking with the version in base by default. It's looking for functions starting with 'SSLv3_', which are not available in more recent versions of OpenSSL such as those in ports, but which are available in the version in base. Attached is the build log from synth with WITH_OPENSSL_PORT=yes. I'm hoping, if I have the time, to take a proper look at the issue some time this week and come up with a patch if I can.
This is not a www/nghttp2 issue but a devel/boost-libs issue. To solve, use patch from https://github.com/pcbsd/freebsd-ports/blob/master/devel/boost-libs/files
A commit references this bug: Author: truckman Date: Mon Mar 14 07:37:49 UTC 2016 New revision: 411050 URL: https://svnweb.freebsd.org/changeset/ports/411050 Log: Import upstream commit bae401b1eb0594932c4e780d496cba852c23b75f to unbreak users of boost/asio/ssl when openssl is built without SSLv3 support. PR: 207429 Changes: head/devel/boost-libs/Makefile head/devel/boost-libs/files/patch-bae401b1eb0594932c4e780d496cba852c23b75f