diff -r 7ed3b4f830c0 Lib/test/regrtest.py
--- a/Lib/test/regrtest.py	Mon Jul 09 13:43:53 2012 -0700
+++ b/Lib/test/regrtest.py	Tue Jul 10 19:51:21 2012 -0700
@@ -634,10 +634,14 @@
                         output.put((None, None, None, None))
                         return
                     # -E is needed by some tests, e.g. test_import
+                    # Running the child from the same working directory ensures
+                    # that TEMPDIR for the child is the same when
+                    # sysconfig.is_python_build() is true. See issue 15300.
                     popen = Popen(base_cmd + ['--slaveargs', json.dumps(args_tuple)],
                                    stdout=PIPE, stderr=PIPE,
                                    universal_newlines=True,
-                                   close_fds=(os.name != 'nt'))
+                                   close_fds=(os.name != 'nt'),
+                                   cwd=support.SAVEDCWD)
                     stdout, stderr = popen.communicate()
                     retcode = popen.wait()
                     # Strip last refcount output line if it exists, since it
diff -r 7ed3b4f830c0 Misc/ACKS
--- a/Misc/ACKS	Mon Jul 09 13:43:53 2012 -0700
+++ b/Misc/ACKS	Tue Jul 10 19:51:21 2012 -0700
@@ -505,6 +505,7 @@
 Drew Jenkins
 Flemming Kjær Jensen
 MunSic Jeong
+Chris Jerdonek
 Jim Jewett
 Orjan Johansen
 Fredrik Johansson
diff -r 7ed3b4f830c0 Misc/NEWS
--- a/Misc/NEWS	Mon Jul 09 13:43:53 2012 -0700
+++ b/Misc/NEWS	Tue Jul 10 19:51:21 2012 -0700
@@ -118,6 +118,10 @@
 - Issue #15284: Skip {send,recv}msg tests in test_socket when IPv6 is not
   enabled. Patch by Brian Brazil.
 
+- Issue #15300: Ensure the temporary test working directories are in the same
+  parent folder when running tests in multiprocess mode from a Python build.
+  Patch by Chris Jerdonek.
+
 - Issue #15277: Fix a resource leak in support.py when IPv6 is disabled.
   Patch by Brian Brazil.