Here is a diff for Go to make use of getexecpath()
for os.Executable().
Tested on aarch64 and amd64.
Index: Makefile
===================================================================
RCS file: /cvs/ports/lang/go/Makefile,v
retrieving revision 1.184
diff -u -p -u -p -r1.184 Makefile
--- Makefile 16 Sep 2026 16:16:51 -0000 1.184
+++ Makefile 4 Oct 2026 09:37:19 -0000
@@ -10,6 +10,7 @@ COMMENT = Go programming language
VERSION = 1.27.1
DISTNAME = go${VERSION}.src
PKGNAME = go-${VERSION}
+REVISION = 0
PKGSPEC = ${FULLPKGNAME:S/go-/go-=/}
CATEGORIES = lang
Index: patches/patch-src_internal_syscall_unix_asm_openbsd_s
===================================================================
RCS file: patches/patch-src_internal_syscall_unix_asm_openbsd_s
diff -N patches/patch-src_internal_syscall_unix_asm_openbsd_s
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-src_internal_syscall_unix_asm_openbsd_s 4 Oct 2026
09:37:19 -0000
@@ -0,0 +1,11 @@
+- Use getexecpath() for os.Executable()
+
+Index: src/internal/syscall/unix/asm_openbsd.s
+--- src/internal/syscall/unix/asm_openbsd.s.orig
++++ src/internal/syscall/unix/asm_openbsd.s
+@@ -22,3 +22,5 @@ TEXT ??libc_linkat_trampoline(SB),NOSPLI
+ JMP libc_linkat(SB)
+ TEXT ??libc_symlinkat_trampoline(SB),NOSPLIT,$0-0
+ JMP libc_symlinkat(SB)
++TEXT ??libc_getexecpath_trampoline(SB),NOSPLIT,$0-0
++ JMP libc_getexecpath(SB)
Index: patches/patch-src_internal_syscall_unix_getexecpath_openbsd_go
===================================================================
RCS file: patches/patch-src_internal_syscall_unix_getexecpath_openbsd_go
diff -N patches/patch-src_internal_syscall_unix_getexecpath_openbsd_go
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-src_internal_syscall_unix_getexecpath_openbsd_go 4 Oct
2026 09:37:19 -0000
@@ -0,0 +1,31 @@
+- Use getexecpath() for os.Executable()
+
+Index: src/internal/syscall/unix/getexecpath_openbsd.go
+--- src/internal/syscall/unix/getexecpath_openbsd.go.orig
++++ src/internal/syscall/unix/getexecpath_openbsd.go
+@@ -0,0 +1,25 @@
++// Copyright 2026 The Go Authors. All rights reserved.
++// Use of this source code is governed by a BSD-style
++// license that can be found in the LICENSE file.
++
++package unix
++
++import (
++ "internal/abi"
++ "unsafe"
++)
++
++//go:cgo_import_dynamic libc_getexecpath getexecpath "libc.so"
++
++func libc_getexecpath_trampoline()
++
++// Getexecpath copies the absolute, canonicalized pathname of the
++// running executable into buf as a NUL-terminated string.
++func Getexecpath(buf []byte) error {
++ _, _, errno :=
syscall_syscall(abi.FuncPCABI0(libc_getexecpath_trampoline),
++ uintptr(unsafe.Pointer(unsafe.SliceData(buf))),
uintptr(len(buf)), 0)
++ if errno != 0 {
++ return errno
++ }
++ return nil
++}
Index: patches/patch-src_os_executable_openbsd_go
===================================================================
RCS file: patches/patch-src_os_executable_openbsd_go
diff -N patches/patch-src_os_executable_openbsd_go
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-src_os_executable_openbsd_go 4 Oct 2026 09:37:19 -0000
@@ -0,0 +1,24 @@
+- Use getexecpath() for os.Executable()
+
+Index: src/os/executable_openbsd.go
+--- src/os/executable_openbsd.go.orig
++++ src/os/executable_openbsd.go
+@@ -0,0 +1,18 @@
++// Copyright 2026 The Go Authors. All rights reserved.
++// Use of this source code is governed by a BSD-style
++// license that can be found in the LICENSE file.
++
++package os
++
++import (
++ "internal/bytealg"
++ "internal/syscall/unix"
++)
++
++func executable() (string, error) {
++ var buf [1024]byte // PATH_MAX; the kernel caps the path at this length
++ if err := unix.Getexecpath(buf[:]); err != nil {
++ return "", NewSyscallError("getexecpath", err)
++ }
++ return string(buf[:bytealg.IndexByte(buf[:], 0)]), nil
++}
Index: patches/patch-src_os_executable_path_go
===================================================================
RCS file: patches/patch-src_os_executable_path_go
diff -N patches/patch-src_os_executable_path_go
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-src_os_executable_path_go 4 Oct 2026 09:37:19 -0000
@@ -0,0 +1,14 @@
+- Use getexecpath() for os.Executable()
+
+Index: src/os/executable_path.go
+--- src/os/executable_path.go.orig
++++ src/os/executable_path.go
+@@ -2,7 +2,7 @@
+ // Use of this source code is governed by a BSD-style
+ // license that can be found in the LICENSE file.
+
+-//go:build aix || openbsd
++//go:build aix
+
+ package os
+
Index: patches/patch-src_os_executable_test_go
===================================================================
RCS file: patches/patch-src_os_executable_test_go
diff -N patches/patch-src_os_executable_test_go
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-src_os_executable_test_go 4 Oct 2026 09:37:19 -0000
@@ -0,0 +1,25 @@
+- Use getexecpath() for os.Executable()
+
+Index: src/os/executable_test.go
+--- src/os/executable_test.go.orig
++++ src/os/executable_test.go
+@@ -48,8 +48,8 @@ func TestExecutable(t *testing.T) {
+ // make child start with a relative program path
+ cmd.Dir = dir
+ cmd.Path = fn
+- if runtime.GOOS == "openbsd" || runtime.GOOS == "aix" {
+- // OpenBSD and AIX rely on argv[0]
++ if runtime.GOOS == "aix" {
++ // AIX relies on argv[0]
+ } else {
+ // forge argv[0] for child, so that we can verify we could
correctly
+ // get real path of the executable without influenced by
argv[0].
+@@ -86,7 +86,7 @@ func TestExecutableDeleted(t *testing.T)
+ switch runtime.GOOS {
+ case "windows", "plan9":
+ t.Skipf("%v does not support deleting running binary",
runtime.GOOS)
+- case "openbsd", "freebsd", "aix":
++ case "freebsd", "aix":
+ t.Skipf("%v does not support reading deleted binary name",
runtime.GOOS)
+ }
+ t.Parallel()
Index: pkg/PLIST
===================================================================
RCS file: /cvs/ports/lang/go/pkg/PLIST,v
retrieving revision 1.100
diff -u -p -u -p -r1.100 PLIST
--- pkg/PLIST 16 Sep 2026 16:16:51 -0000 1.100
+++ pkg/PLIST 4 Oct 2026 09:37:20 -0000
@@ -9188,6 +9188,7 @@ go/src/internal/syscall/unix/fchmodat_te
go/src/internal/syscall/unix/fcntl_js.go
go/src/internal/syscall/unix/fcntl_unix.go
go/src/internal/syscall/unix/fcntl_wasip1.go
+go/src/internal/syscall/unix/getexecpath_openbsd.go
go/src/internal/syscall/unix/getrandom.go
go/src/internal/syscall/unix/getrandom_dragonfly.go
go/src/internal/syscall/unix/getrandom_freebsd.go
@@ -10843,6 +10844,7 @@ go/src/os/executable_darwin.go
go/src/os/executable_dragonfly.go
go/src/os/executable_freebsd.go
go/src/os/executable_netbsd.go
+go/src/os/executable_openbsd.go
go/src/os/executable_path.go
go/src/os/executable_plan9.go
go/src/os/executable_procfs.go
