https://github.com/mitchellh/go-ps/pull/45

Index: vendor/github.com/mitchellh/go-ps/process_openbsd.h
--- vendor/github.com/mitchellh/go-ps/process_openbsd.h.orig
+++ vendor/github.com/mitchellh/go-ps/process_openbsd.h
@@ -0,0 +1,31 @@
+// +build openbsd
+
+#include <errno.h>
+#include <stdio.h>
+#include <kvm.h>
+#include <limits.h>
+#include <sys/param.h>
+#include <sys/sysctl.h>
+
+extern void go_openbsd_append_proc(pid_t, pid_t, char *);
+
+static inline int openbsdProcesses() {
+	int nentries = 0;
+	int i = 0;
+	char errbuf[_POSIX2_LINE_MAX];
+	struct kinfo_proc *result = NULL;
+	kvm_t *kernel = kvm_openfiles(NULL, NULL, NULL, KVM_NO_FILES, errbuf);
+	if (!kernel) {
+		return errno; 
+	} 
+	result = kvm_getprocs(kernel, KERN_PROC_ALL, 0, sizeof(struct kinfo_proc), &nentries);
+	for (i = 0; i < nentries; i++) {
+		struct kinfo_proc *single = &result[i]; 
+		go_openbsd_append_proc(
+			single->p_pid,
+			single->p_ppid,
+			single->p_comm);
+	}
+
+	return 0;
+}
