I took this fix from Debian [0]. It builds and works fine on amd64 and macppc.
OK? Charlène. [0] https://sources.debian.org/patches/wmweather/2.4.7-3/957956_gcc10.diff/ Index: Makefile =================================================================== RCS file: /cvs/ports/x11/wmweather/Makefile,v retrieving revision 1.30 diff -u -p -u -p -r1.30 Makefile --- Makefile 12 Jul 2019 20:51:24 -0000 1.30 +++ Makefile 1 Feb 2021 13:55:54 -0000 @@ -3,6 +3,7 @@ COMMENT= wm-dockapp; weather monitor DISTNAME= wmweather-2.4.7 +REVISION= 0 CATEGORIES= x11 x11/windowmaker HOMEPAGE= http://people.debian.org/~godisch/wmweather/ Index: patches/patch-src_wmgeneral_c =================================================================== RCS file: patches/patch-src_wmgeneral_c diff -N patches/patch-src_wmgeneral_c --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ patches/patch-src_wmgeneral_c 1 Feb 2021 13:55:54 -0000 @@ -0,0 +1,15 @@ +$OpenBSD$ + +Fix the build with -fno-common + +Index: src/wmgeneral.c +--- src/wmgeneral.c.orig ++++ src/wmgeneral.c +@@ -85,6 +85,7 @@ Window iconwin, win; + GC NormalGC; + XpmIcon wmgen; + Pixmap pixmask; ++Display *display; + + /*****************/ + /* Mouse Regions */ Index: patches/patch-src_wmgeneral_h =================================================================== RCS file: patches/patch-src_wmgeneral_h diff -N patches/patch-src_wmgeneral_h --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ patches/patch-src_wmgeneral_h 1 Feb 2021 13:55:54 -0000 @@ -0,0 +1,16 @@ +$OpenBSD$ + +Fix the build with -fno-common + +Index: src/wmgeneral.h +--- src/wmgeneral.h.orig ++++ src/wmgeneral.h +@@ -36,7 +36,7 @@ typedef struct { + /* Global variable */ + /*******************/ + +-Display *display; ++extern Display *display; + + /***********************/ + /* Function Prototypes */
