--- Libc/Libc-997.90.3/stdlib/FreeBSD/abort.c
+++ Libc/Libc-825.26/stdlib/FreeBSD/abort.c
@@ -40,7 +40,6 @@
 #include <stddef.h>
 #include <unistd.h>
 #include <pthread.h>
-#include <pthread_workqueue.h>
 #include "un-namespace.h"
 
 #include "libc_private.h"
@@ -78,18 +77,21 @@
 	/* <rdar://problem/7397932> abort() should call pthread_kill to deliver a signal to the aborting thread 
 	 * This helps gdb focus on the thread calling abort()
 	 */
+	if (__is_threaded) {
+	    /* Block all signals on all other threads */
+	    sigset_t fullmask;
+	    sigfillset(&fullmask);
+	    (void)_sigprocmask(SIG_SETMASK, &fullmask, NULL);
 
-	/* Block all signals on all other threads */
-	sigset_t fullmask;
-	sigfillset(&fullmask);
-	(void)_sigprocmask(SIG_SETMASK, &fullmask, NULL);
+	    /* <rdar://problem/8400096> Set the workqueue killable */
+	    __pthread_workqueue_setkill(1);
 
-	/* <rdar://problem/8400096> Set the workqueue killable */
-	__pthread_workqueue_setkill(1);
-
-	(void)pthread_sigmask(SIG_SETMASK, &act.sa_mask, NULL);
-	(void)pthread_kill(pthread_self(), SIGABRT);
-
+	    (void)pthread_sigmask(SIG_SETMASK, &act.sa_mask, NULL);
+	    (void)pthread_kill(pthread_self(), SIGABRT);
+	} else {
+	    (void)_sigprocmask(SIG_SETMASK, &act.sa_mask, NULL);
+	    (void)kill(getpid(), SIGABRT);
+	}
 	usleep(TIMEOUT); /* give time for signal to happen */
 
 	/*
@@ -115,18 +117,21 @@
 	/* <rdar://problem/7397932> abort() should call pthread_kill to deliver a signal to the aborting thread 
 	 * This helps gdb focus on the thread calling abort()
 	 */
+	if (__is_threaded) {
+	    /* Block all signals on all other threads */
+	    sigset_t fullmask;
+	    sigfillset(&fullmask);
+	    (void)_sigprocmask(SIG_SETMASK, &fullmask, NULL);
 
-	/* Block all signals on all other threads */
-	sigset_t fullmask;
-	sigfillset(&fullmask);
-	(void)_sigprocmask(SIG_SETMASK, &fullmask, NULL);
+	    /* <rdar://problem/8400096> Set the workqueue killable */
+	    __pthread_workqueue_setkill(1);
 
-	/* <rdar://problem/8400096> Set the workqueue killable */
-	__pthread_workqueue_setkill(1);
-
-	(void)pthread_sigmask(SIG_SETMASK, &act.sa_mask, NULL);
-	(void)pthread_kill(pthread_self(), SIGABRT);
-
+	    (void)pthread_sigmask(SIG_SETMASK, &act.sa_mask, NULL);
+	    (void)pthread_kill(pthread_self(), SIGABRT);
+	} else {
+	    (void)_sigprocmask(SIG_SETMASK, &act.sa_mask, NULL);
+	    (void)kill(getpid(), SIGABRT);
+	}
 	usleep(TIMEOUT); /* give time for signal to happen */
 
 	/* If for some reason SIGABRT was not delivered, we exit using __builtin_trap