The 3.30.1 update to syslog-ng breaks the build with a non-default Python version. Line 184 of the Makefile should not have Python 3.7 hardcoded in the file name.
Created attachment 220952 [details] Patch
Needs a port revision bump as well. I can take care of it.
A commit references this bug: Author: cy Date: Wed Dec 30 05:51:10 UTC 2020 New revision: 559641 URL: https://svnweb.freebsd.org/changeset/ports/559641 Log: Fix build with broken nondefault python. PR: 251343 Submitted by: Christian Ullrich <chris _ chrullrich.net> Changes: head/sysutils/syslog-ng/Makefile
Fixed.