Commit 791177d is required to build the latest release on arm, I stripped down the patch leaving out the comments. The patch has to be removed in the next version update anyway:
Index: Makefile =================================================================== RCS file: /cvs/ports/security/libgpg-error/Makefile,v retrieving revision 1.40 diff -u -p -r1.40 Makefile --- Makefile 17 Mar 2018 08:49:24 -0000 1.40 +++ Makefile 22 Mar 2018 07:13:19 -0000 @@ -3,6 +3,7 @@ COMMENT= error codes for GnuPG related software DISTNAME= libgpg-error-1.28 +REVISION= 0 CATEGORIES= security devel EXTRACT_SUFX= .tar.bz2 Index: patches/patch-src_logging_c =================================================================== RCS file: patches/patch-src_logging_c diff -N patches/patch-src_logging_c --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ patches/patch-src_logging_c 22 Mar 2018 07:13:19 -0000 @@ -0,0 +1,18 @@ +$OpenBSD$ + +Index: src/logging.c +--- src/logging.c.orig ++++ src/logging.c +@@ -1150,7 +1150,11 @@ _gpgrt_log_printhex (const void *buffer, size_t length + va_end (arg_ptr); + } + else +- _gpgrt_logv_printhex (buffer, length, NULL, NULL); ++ { ++ static va_list dummy_argptr; ++ ++ _gpgrt_logv_printhex (buffer, length, NULL, dummy_argptr); ++ } + } + +