This was brought to my attention as a build error with LibreSSL 2.9 (security/libressl-devel). The OpenBSD ports collection has a patch for correcting some preprocessor directives to keep up to date with LibreSSL's supported features. This also fixes the aforementioned build error with LibreSSL 2.9. Passes testport.
It should also be mentioned that upstream merged this patch, but only for the 1.86 development releases and later.
LibreSSL 2.9(.1) is now stable (security/libressl). The build-error has now "moved" there as well.
A commit references this bug:
Date: Tue Apr 23 09:24:56 UTC 2019
New revision: 499739
security/p5-Net-SSLeay: fix build with libressl 2.9
I'm considering a maintainer timeout for this one, as the bug was first
reported in December. LibreSSL 2.9.1 is now the main version in the ports tree,
so this is urgent.
perl@, feel free to commit a better fix.
Submitted by: Charlie Li <firstname.lastname@example.org>
Approved by: maintainer (timeout)