diff --git a/changes/bug27968 b/changes/bug27968
new file mode 100644
index 0000000000..78c8eee33a
--- /dev/null
+++ b/changes/bug27968
@@ -0,0 +1,3 @@
+  o Minor bugfixes (testing):
+    - Avoid hangs and race conditions in test_rebind.py.
+      Fixes bug 27968; bugfix on 0.3.5.1-alpha.
diff --git a/src/test/test_rebind.py b/src/test/test_rebind.py
index 7ba3a5796d..c63341a681 100644
--- a/src/test/test_rebind.py
+++ b/src/test/test_rebind.py
@@ -1,25 +1,42 @@
 from __future__ import print_function
 
-import sys
-import subprocess
-import socket
+import errno
 import os
-import time
 import random
+import socket
+import subprocess
+import sys
+import time
+
+LOG_TIMEOUT = 60.0
+LOG_WAIT = 0.1
+LOG_CHECK_LIMIT = LOG_TIMEOUT / LOG_WAIT
+
+def fail(msg):
+    print('FAIL')
+    sys.exit(msg)
 
 def try_connecting_to_socksport():
     socks_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     if socks_socket.connect_ex(('127.0.0.1', socks_port)):
         tor_process.terminate()
-        print('FAIL')
-        sys.exit('Cannot connect to SOCKSPort')
+        fail('Cannot connect to SOCKSPort')
     socks_socket.close()
 
 def wait_for_log(s):
-    while True:
+    log_checked = 0
+    while log_checked < LOG_CHECK_LIMIT:
         l = tor_process.stdout.readline()
-        if s in l.decode('utf8'):
+        l = l.decode('utf8')
+        if s in l:
             return
+        print('Tor logged: "{}", waiting for "{}"'.format(l.strip(), s))
+        # readline() returns a blank string when there is no output
+        # avoid busy-waiting
+        if len(s) == 0:
+            time.sleep(LOG_WAIT)
+        log_checked += 1
+    fail('Could not find "{}" in logs after {} seconds'.format(s, LOG_TIMEOUT))
 
 def pick_random_port():
     port = 0
@@ -33,13 +50,16 @@ def pick_random_port():
         else:
             break
 
+    if port == 0:
+        fail('Could not find a random free port between 10000 and 60000')
+
     return port
 
 if sys.hexversion < 0x02070000:
-    sys.exit("ERROR: unsupported Python version (should be >= 2.7)")
+    fail("ERROR: unsupported Python version (should be >= 2.7)")
 
 if sys.hexversion > 0x03000000 and sys.hexversion < 0x03010000:
-    sys.exit("ERROR: unsupported Python3 version (should be >= 3.1)")
+    fail("ERROR: unsupported Python3 version (should be >= 3.1)")
 
 control_port = pick_random_port()
 socks_port = pick_random_port()
@@ -48,7 +68,7 @@ assert control_port != 0
 assert socks_port != 0
 
 if not os.path.exists(sys.argv[1]):
-    sys.exit('ERROR: cannot find tor at %s' % sys.argv[1])
+    fail('ERROR: cannot find tor at %s' % sys.argv[1])
 
 tor_path = sys.argv[1]
 
@@ -60,10 +80,10 @@ tor_process = subprocess.Popen([tor_path,
                                stderr=subprocess.PIPE)
 
 if tor_process == None:
-    sys.exit('ERROR: running tor failed')
+    fail('ERROR: running tor failed')
 
 if len(sys.argv) < 2:
-     sys.exit('Usage: %s <path-to-tor>' % sys.argv[0])
+     fail('Usage: %s <path-to-tor>' % sys.argv[0])
 
 wait_for_log('Opened Control listener on')
 
@@ -72,8 +92,7 @@ try_connecting_to_socksport()
 control_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 if control_socket.connect_ex(('127.0.0.1', control_port)):
     tor_process.terminate()
-    print('FAIL')
-    sys.exit('Cannot connect to ControlPort')
+    fail('Cannot connect to ControlPort')
 
 control_socket.sendall('AUTHENTICATE \r\n'.encode('utf8'))
 control_socket.sendall('SETCONF SOCKSPort=0.0.0.0:{}\r\n'.format(socks_port).encode('utf8'))
@@ -88,6 +107,14 @@ try_connecting_to_socksport()
 
 control_socket.sendall('SIGNAL HALT\r\n'.encode('utf8'))
 
-time.sleep(0.1)
+wait_for_log('exiting cleanly')
 print('OK')
-tor_process.terminate()
+
+try:
+    tor_process.terminate()
+except OSError as e:
+    if e.errno == errno.ESRCH: # errno 3: No such process
+        # assume tor has already exited due to SIGNAL HALT
+        print("Tor has already exited")
+    else:
+        raise