Here is a diff to SDL3 to add getexecpath() support.
Index: Makefile
===================================================================
RCS file: /cvs/ports/devel/sdl3/Makefile,v
retrieving revision 1.9
diff -u -p -u -p -r1.9 Makefile
--- Makefile 8 Sep 2026 12:45:28 -0000 1.9
+++ Makefile 11 Sep 2026 06:31:18 -0000
@@ -3,6 +3,7 @@ COMMENT = cross-platform multimedia lib
V = 3.4.16
DISTNAME = SDL3-${V}
PKGNAME = ${DISTNAME:L}
+REVISION = 0
SHARED_LIBS += SDL3 0.1 # 3.4.0
Index: patches/patch-CMakeLists_txt
===================================================================
RCS file: patches/patch-CMakeLists_txt
diff -N patches/patch-CMakeLists_txt
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-CMakeLists_txt 11 Sep 2026 06:31:18 -0000
@@ -0,0 +1,14 @@
+- fs: Use getexecpath() on OpenBSD for GetExePath().
+ b7606be372bff4f434d0e2e06ca8a1edd249cde4
+
+Index: CMakeLists.txt
+--- CMakeLists.txt.orig
++++ CMakeLists.txt
+@@ -1159,6 +1159,7 @@ if(SDL_LIBC)
+
+ if(NOT WINDOWS)
+ check_symbol_exists(fdatasync "unistd.h" HAVE_FDATASYNC)
++ check_symbol_exists(getexecpath "unistd.h" HAVE_GETEXECPATH)
+ check_symbol_exists(gethostname "unistd.h" HAVE_GETHOSTNAME)
+ check_symbol_exists(getpagesize "unistd.h" HAVE_GETPAGESIZE)
+ check_symbol_exists(getresgid "unistd.h" HAVE_GETRESGID)
Index: patches/patch-include_build_config_SDL_build_config_h_cmake
===================================================================
RCS file: patches/patch-include_build_config_SDL_build_config_h_cmake
diff -N patches/patch-include_build_config_SDL_build_config_h_cmake
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-include_build_config_SDL_build_config_h_cmake 11 Sep 2026
06:31:18 -0000
@@ -0,0 +1,14 @@
+- fs: Follow up to the initial getexecpath() support
+ c545b20bd7fbd536a37c00271e6d474acc861a34
+
+Index: include/build_config/SDL_build_config.h.cmake
+--- include/build_config/SDL_build_config.h.cmake.orig
++++ include/build_config/SDL_build_config.h.cmake
+@@ -73,6 +73,7 @@
+ #cmakedefine HAVE_DLOPEN 1
+ #cmakedefine HAVE_MALLOC 1
+ #cmakedefine HAVE_FDATASYNC 1
++#cmakedefine HAVE_GETEXECPATH 1
+ #cmakedefine HAVE_GETENV 1
+ #cmakedefine HAVE_GETHOSTNAME 1
+ #cmakedefine HAVE_SETENV 1
Index: patches/patch-src_filesystem_unix_SDL_sysfilesystem_c
===================================================================
RCS file: patches/patch-src_filesystem_unix_SDL_sysfilesystem_c
diff -N patches/patch-src_filesystem_unix_SDL_sysfilesystem_c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-src_filesystem_unix_SDL_sysfilesystem_c 11 Sep 2026
06:31:18 -0000
@@ -0,0 +1,41 @@
+- fs: Use getexecpath() on OpenBSD for GetExePath().
+ b7606be372bff4f434d0e2e06ca8a1edd249cde4
+- fs: Follow up to the initial getexecpath() support
+ c545b20bd7fbd536a37c00271e6d474acc861a34
+
+Index: src/filesystem/unix/SDL_sysfilesystem.c
+--- src/filesystem/unix/SDL_sysfilesystem.c.orig
++++ src/filesystem/unix/SDL_sysfilesystem.c
+@@ -71,7 +71,7 @@ static char *readSymLink(const char *path)
+ return NULL;
+ }
+
+-#ifdef SDL_PLATFORM_OPENBSD
++#if defined(SDL_PLATFORM_OPENBSD) && !defined(HAVE_GETEXECPATH)
+ static char *search_path_for_binary(const char *bin)
+ {
+ const char *envr_real = SDL_getenv("PATH");
+@@ -138,6 +138,15 @@ static char *GetExePath(void)
+ }
+ #endif
+ #ifdef SDL_PLATFORM_OPENBSD
++#ifdef HAVE_GETEXECPATH
++ char fullpath[PATH_MAX];
++ if (getexecpath(fullpath, sizeof(fullpath)) == 0) {
++ result = SDL_strdup(fullpath);
++ if (!result) {
++ return NULL;
++ }
++ }
++#else
+ // Please note that this will fail if the process was launched with a
relative path and $PWD + the cwd have changed, or argv is altered. So don't do
that. Or add a new sysctl to OpenBSD.
+ char **cmdline;
+ size_t len;
+@@ -193,6 +202,7 @@ static char *GetExePath(void)
+
+ SDL_free(cmdline);
+ }
++#endif
+ #endif
+
+ // is a Linux-style /proc filesystem available?
