run-tests: don't replace PYTHONPATH, just augment it.

(Needed at least for Subversion bindings on OS X, which are in
/opt/subversion.  Useful for other external libraries installed in
non-standard places too.)

tests/run-tests.py

@@ -1,791 +1,794 b''
 #!/usr/bin/env python
 #
 # run-tests.py - Run a set of tests on Mercurial
 #
 # Copyright 2006 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2, incorporated herein by reference.
 
 # Modifying this script is tricky because it has many modes:
 #   - serial (default) vs parallel (-jN, N > 1)
 #   - no coverage (default) vs coverage (-c, -C, -s)
 #   - temp install (default) vs specific hg script (--with-hg, --local)
 #   - tests are a mix of shell scripts and Python scripts
 #
 # If you change this script, it is recommended that you ensure you
 # haven't broken it by running it in various modes with a representative
 # sample of test scripts.  For example:
 # 
 #  1) serial, no coverage, temp install:
 #      ./run-tests.py test-s*
 #  2) serial, no coverage, local hg:
 #      ./run-tests.py --local test-s*
 #  3) serial, coverage, temp install:
 #      ./run-tests.py -c test-s*
 #  4) serial, coverage, local hg:
 #      ./run-tests.py -c --local test-s*      # unsupported
 #  5) parallel, no coverage, temp install:
 #      ./run-tests.py -j2 test-s*
 #  6) parallel, no coverage, local hg:
 #      ./run-tests.py -j2 --local test-s*
 #  7) parallel, coverage, temp install:
 #      ./run-tests.py -j2 -c test-s*          # currently broken
 #  8) parallel, coverage, local install
 #      ./run-tests.py -j2 -c --local test-s*  # unsupported (and broken)
 #
 # (You could use any subset of the tests: test-s* happens to match
 # enough that it's worth doing parallel runs, few enough that it
 # completes fairly quickly, includes both shell and Python scripts, and
 # includes some scripts that run daemon processes.)
 
 import difflib
 import errno
 import optparse
 import os
 import subprocess
 import shutil
 import signal
 import sys
 import tempfile
 import time
 
 closefds = os.name == 'posix'
 def Popen4(cmd, bufsize=-1):
     p = subprocess.Popen(cmd, shell=True, bufsize=bufsize,
                          close_fds=closefds,
                          stdin=subprocess.PIPE, stdout=subprocess.PIPE,
                          stderr=subprocess.STDOUT)
     p.fromchild = p.stdout
     p.tochild = p.stdin
     p.childerr = p.stderr
     return p
 
 # reserved exit code to skip test (used by hghave)
 SKIPPED_STATUS = 80
 SKIPPED_PREFIX = 'skipped: '
 FAILED_PREFIX  = 'hghave check failed: '
 PYTHON = sys.executable
 
 requiredtools = ["python", "diff", "grep", "unzip", "gunzip", "bunzip2", "sed"]
 
 defaults = {
     'jobs': ('HGTEST_JOBS', 1),
     'timeout': ('HGTEST_TIMEOUT', 180),
     'port': ('HGTEST_PORT', 20059),
 }
 
 def parseargs():
     parser = optparse.OptionParser("%prog [options] [tests]")
     parser.add_option("-C", "--annotate", action="store_true",
         help="output files annotated with coverage")
     parser.add_option("--child", type="int",
         help="run as child process, summary to given fd")
     parser.add_option("-c", "--cover", action="store_true",
         help="print a test coverage report")
     parser.add_option("-f", "--first", action="store_true",
         help="exit on the first test failure")
     parser.add_option("-i", "--interactive", action="store_true",
         help="prompt to accept changed output")
     parser.add_option("-j", "--jobs", type="int",
         help="number of jobs to run in parallel"
              " (default: $%s or %d)" % defaults['jobs'])
     parser.add_option("--keep-tmpdir", action="store_true",
         help="keep temporary directory after running tests"
              " (best used with --tmpdir)")
     parser.add_option("-R", "--restart", action="store_true",
         help="restart at last error")
     parser.add_option("-p", "--port", type="int",
         help="port on which servers should listen"
              " (default: $%s or %d)" % defaults['port'])
     parser.add_option("-r", "--retest", action="store_true",
         help="retest failed tests")
     parser.add_option("-s", "--cover_stdlib", action="store_true",
         help="print a test coverage report inc. standard libraries")
     parser.add_option("-t", "--timeout", type="int",
         help="kill errant tests after TIMEOUT seconds"
              " (default: $%s or %d)" % defaults['timeout'])
     parser.add_option("--tmpdir", type="string",
         help="run tests in the given temporary directory")
     parser.add_option("-v", "--verbose", action="store_true",
         help="output verbose messages")
     parser.add_option("-n", "--nodiff", action="store_true",
         help="skip showing test changes")
     parser.add_option("--with-hg", type="string",
         metavar="HG",
         help="test using specified hg script rather than a "
              "temporary installation")
     parser.add_option("--local", action="store_true",
         help="shortcut for --with-hg=<testdir>/../hg")
     parser.add_option("--pure", action="store_true",
         help="use pure Python code instead of C extensions")
 
     for option, default in defaults.items():
         defaults[option] = int(os.environ.get(*default))
     parser.set_defaults(**defaults)
     (options, args) = parser.parse_args()
 
     if options.with_hg:
         if not (os.path.isfile(options.with_hg) and
                 os.access(options.with_hg, os.X_OK)):
             parser.error('--with-hg must specify an executable hg script')
         if not os.path.basename(options.with_hg) == 'hg':
             sys.stderr.write('warning: --with-hg should specify an hg script')
     if options.local:
         testdir = os.path.dirname(os.path.realpath(sys.argv[0]))
         hgbin = os.path.join(os.path.dirname(testdir), 'hg')
         if not os.access(hgbin, os.X_OK):
             parser.error('--local specified, but %r not found or not executable'
                          % hgbin)
         options.with_hg = hgbin
 
     options.anycoverage = (options.cover or
                            options.cover_stdlib or
                            options.annotate)
 
     if options.anycoverage and options.with_hg:
         # I'm not sure if this is a fundamental limitation or just a
         # bug.  But I don't want to waste people's time and energy doing
         # test runs that don't give the results they want.
         parser.error("sorry, coverage options do not work when --with-hg "
                      "or --local specified")
 
     global vlog
     if options.verbose:
         if options.jobs > 1 or options.child is not None:
             pid = "[%d]" % os.getpid()
         else:
             pid = None
         def vlog(*msg):
             if pid:
                 print pid,
             for m in msg:
                 print m,
             print
     else:
         vlog = lambda *msg: None
 
     if options.jobs < 1:
         print >> sys.stderr, 'ERROR: -j/--jobs must be positive'
         sys.exit(1)
     if options.interactive and options.jobs > 1:
         print '(--interactive overrides --jobs)'
         options.jobs = 1
 
     return (options, args)
 
 def rename(src, dst):
     """Like os.rename(), trade atomicity and opened files friendliness
     for existing destination support.
     """
     shutil.copy(src, dst)
     os.remove(src)
 
 def splitnewlines(text):
     '''like str.splitlines, but only split on newlines.
     keep line endings.'''
     i = 0
     lines = []
     while True:
         n = text.find('\n', i)
         if n == -1:
             last = text[i:]
             if last:
                 lines.append(last)
             return lines
         lines.append(text[i:n+1])
         i = n + 1
 
 def parsehghaveoutput(lines):
     '''Parse hghave log lines.
     Return tuple of lists (missing, failed):
       * the missing/unknown features
       * the features for which existence check failed'''
     missing = []
     failed = []
     for line in lines:
         if line.startswith(SKIPPED_PREFIX):
             line = line.splitlines()[0]
             missing.append(line[len(SKIPPED_PREFIX):])
         elif line.startswith(FAILED_PREFIX):
             line = line.splitlines()[0]
             failed.append(line[len(FAILED_PREFIX):])
 
     return missing, failed
 
 def showdiff(expected, output):
     for line in difflib.unified_diff(expected, output,
             "Expected output", "Test output"):
         sys.stdout.write(line)
 
 def findprogram(program):
     """Search PATH for a executable program"""
     for p in os.environ.get('PATH', os.defpath).split(os.pathsep):
         name = os.path.join(p, program)
         if os.access(name, os.X_OK):
             return name
     return None
 
 def checktools():
     # Before we go any further, check for pre-requisite tools
     # stuff from coreutils (cat, rm, etc) are not tested
     for p in requiredtools:
         if os.name == 'nt':
             p += '.exe'
         found = findprogram(p)
         if found:
             vlog("# Found prerequisite", p, "at", found)
         else:
             print "WARNING: Did not find prerequisite tool: "+p
 
 def cleanup(options):
     if not options.keep_tmpdir:
         vlog("# Cleaning up HGTMP", HGTMP)
         shutil.rmtree(HGTMP, True)
 
 def usecorrectpython():
     # some tests run python interpreter. they must use same
     # interpreter we use or bad things will happen.
     exedir, exename = os.path.split(sys.executable)
     if exename == 'python':
         path = findprogram('python')
         if os.path.dirname(path) == exedir:
             return
     vlog('# Making python executable in test path use correct Python')
     mypython = os.path.join(BINDIR, 'python')
     try:
         os.symlink(sys.executable, mypython)
     except AttributeError:
         # windows fallback
         shutil.copyfile(sys.executable, mypython)
         shutil.copymode(sys.executable, mypython)
 
 def installhg(options):
     vlog("# Performing temporary installation of HG")
     installerrs = os.path.join("tests", "install.err")
     pure = options.pure and "--pure" or ""
 
     # Run installer in hg root
     os.chdir(os.path.join(os.path.dirname(sys.argv[0]), '..'))
     cmd = ('%s setup.py %s clean --all'
            ' install --force --prefix="%s" --install-lib="%s"'
            ' --install-scripts="%s" >%s 2>&1'
            % (sys.executable, pure, INST, PYTHONDIR, BINDIR, installerrs))
     vlog("# Running", cmd)
     if os.system(cmd) == 0:
         if not options.verbose:
             os.remove(installerrs)
     else:
         f = open(installerrs)
         for line in f:
             print line,
         f.close()
         sys.exit(1)
     os.chdir(TESTDIR)
 
     usecorrectpython()
 
     vlog("# Installing dummy diffstat")
     f = open(os.path.join(BINDIR, 'diffstat'), 'w')
     f.write('#!' + sys.executable + '\n'
             'import sys\n'
             'files = 0\n'
             'for line in sys.stdin:\n'
             '    if line.startswith("diff "):\n'
             '        files += 1\n'
             'sys.stdout.write("files patched: %d\\n" % files)\n')
     f.close()
     os.chmod(os.path.join(BINDIR, 'diffstat'), 0700)
 
     if options.anycoverage:
         vlog("# Installing coverage wrapper")
         os.environ['COVERAGE_FILE'] = COVERAGE_FILE
         if os.path.exists(COVERAGE_FILE):
             os.unlink(COVERAGE_FILE)
         # Create a wrapper script to invoke hg via coverage.py
         os.rename(os.path.join(BINDIR, "hg"), os.path.join(BINDIR, "_hg.py"))
         f = open(os.path.join(BINDIR, 'hg'), 'w')
         f.write('#!' + sys.executable + '\n')
         f.write('import sys, os; os.execv(sys.executable, [sys.executable, '
                 '"%s", "-x", "-p", "%s"] + sys.argv[1:])\n' %
                 (os.path.join(TESTDIR, 'coverage.py'),
                  os.path.join(BINDIR, '_hg.py')))
         f.close()
         os.chmod(os.path.join(BINDIR, 'hg'), 0700)
 
 def outputcoverage(options):
 
     vlog('# Producing coverage report')
     os.chdir(PYTHONDIR)
 
     def covrun(*args):
         start = sys.executable, os.path.join(TESTDIR, 'coverage.py')
         cmd = '"%s" "%s" %s' % (start[0], start[1], ' '.join(args))
         vlog('# Running: %s' % cmd)
         os.system(cmd)
 
     omit = [BINDIR, TESTDIR, PYTHONDIR]
     if not options.cover_stdlib:
         # Exclude as system paths (ignoring empty strings seen on win)
         omit += [x for x in sys.path if x != '']
     omit = ','.join(omit)
 
     covrun('-c') # combine from parallel processes
     covrun('-i', '-r', '"--omit=%s"' % omit) # report
     if options.annotate:
         adir = os.path.join(TESTDIR, 'annotated')
         if not os.path.isdir(adir):
             os.mkdir(adir)
         covrun('-i', '-a', '"--directory=%s"' % adir, '"--omit=%s"' % omit)
 
 class Timeout(Exception):
     pass
 
 def alarmed(signum, frame):
     raise Timeout
 
 def run(cmd, options):
     """Run command in a sub-process, capturing the output (stdout and stderr).
     Return the exist code, and output."""
     # TODO: Use subprocess.Popen if we're running on Python 2.4
     if os.name == 'nt' or sys.platform.startswith('java'):
         tochild, fromchild = os.popen4(cmd)
         tochild.close()
         output = fromchild.read()
         ret = fromchild.close()
         if ret == None:
             ret = 0
     else:
         proc = Popen4(cmd)
         try:
             output = ''
             proc.tochild.close()
             output = proc.fromchild.read()
             ret = proc.wait()
             if os.WIFEXITED(ret):
                 ret = os.WEXITSTATUS(ret)
         except Timeout:
             vlog('# Process %d timed out - killing it' % proc.pid)
             os.kill(proc.pid, signal.SIGTERM)
             ret = proc.wait()
             if ret == 0:
                 ret = signal.SIGTERM << 8
             output += ("\n### Abort: timeout after %d seconds.\n"
                        % options.timeout)
     return ret, splitnewlines(output)
 
 def runone(options, test, skips, fails):
     '''tristate output:
     None -> skipped
     True -> passed
     False -> failed'''
 
     def skip(msg):
         if not options.verbose:
             skips.append((test, msg))
         else:
             print "\nSkipping %s: %s" % (test, msg)
         return None
 
     def fail(msg):
         fails.append((test, msg))
         if not options.nodiff:
             print "\nERROR: %s %s" % (test, msg)
         return None
 
     vlog("# Test", test)
 
     # create a fresh hgrc
     hgrc = file(HGRCPATH, 'w+')
     hgrc.write('[ui]\n')
     hgrc.write('slash = True\n')
     hgrc.write('[defaults]\n')
     hgrc.write('backout = -d "0 0"\n')
     hgrc.write('commit = -d "0 0"\n')
     hgrc.write('tag = -d "0 0"\n')
     hgrc.close()
 
     err = os.path.join(TESTDIR, test+".err")
     ref = os.path.join(TESTDIR, test+".out")
     testpath = os.path.join(TESTDIR, test)
 
     if os.path.exists(err):
         os.remove(err)       # Remove any previous output files
 
     # Make a tmp subdirectory to work in
     tmpd = os.path.join(HGTMP, test)
     os.mkdir(tmpd)
     os.chdir(tmpd)
 
     try:
         tf = open(testpath)
         firstline = tf.readline().rstrip()
         tf.close()
     except:
         firstline = ''
     lctest = test.lower()
 
     if lctest.endswith('.py') or firstline == '#!/usr/bin/env python':
         cmd = '%s "%s"' % (PYTHON, testpath)
     elif lctest.endswith('.bat'):
         # do not run batch scripts on non-windows
         if os.name != 'nt':
             return skip("batch script")
         # To reliably get the error code from batch files on WinXP,
         # the "cmd /c call" prefix is needed. Grrr
         cmd = 'cmd /c call "%s"' % testpath
     else:
         # do not run shell scripts on windows
         if os.name == 'nt':
             return skip("shell script")
         # do not try to run non-executable programs
         if not os.path.exists(testpath):
             return fail("does not exist")
         elif not os.access(testpath, os.X_OK):
             return skip("not executable")
         cmd = '"%s"' % testpath
 
     if options.timeout > 0:
         signal.alarm(options.timeout)
 
     vlog("# Running", cmd)
     ret, out = run(cmd, options)
     vlog("# Ret was:", ret)
 
     if options.timeout > 0:
         signal.alarm(0)
 
     mark = '.'
 
     skipped = (ret == SKIPPED_STATUS)
     # If reference output file exists, check test output against it
     if os.path.exists(ref):
         f = open(ref, "r")
         refout = splitnewlines(f.read())
         f.close()
     else:
         refout = []
     if skipped:
         mark = 's'
         missing, failed = parsehghaveoutput(out)
         if not missing:
             missing = ['irrelevant']
         if failed:
             fail("hghave failed checking for %s" % failed[-1])
             skipped = False
         else:
             skip(missing[-1])
     elif out != refout:
         mark = '!'
         if ret:
             fail("output changed and returned error code %d" % ret)
         else:
             fail("output changed")
         if not options.nodiff:
             showdiff(refout, out)
         ret = 1
     elif ret:
         mark = '!'
         fail("returned error code %d" % ret)
 
     if not options.verbose:
         sys.stdout.write(mark)
         sys.stdout.flush()
 
     if ret != 0 and not skipped:
         # Save errors to a file for diagnosis
         f = open(err, "wb")
         for line in out:
             f.write(line)
         f.close()
 
     # Kill off any leftover daemon processes
     try:
         fp = file(DAEMON_PIDS)
         for line in fp:
             try:
                 pid = int(line)
             except ValueError:
                 continue
             try:
                 os.kill(pid, 0)
                 vlog('# Killing daemon process %d' % pid)
                 os.kill(pid, signal.SIGTERM)
                 time.sleep(0.25)
                 os.kill(pid, 0)
                 vlog('# Daemon process %d is stuck - really killing it' % pid)
                 os.kill(pid, signal.SIGKILL)
             except OSError, err:
                 if err.errno != errno.ESRCH:
                     raise
         fp.close()
         os.unlink(DAEMON_PIDS)
     except IOError:
         pass
 
     os.chdir(TESTDIR)
     if not options.keep_tmpdir:
         shutil.rmtree(tmpd, True)
     if skipped:
         return None
     return ret == 0
 
 _hgpath = None
 
 def _gethgpath():
     """Return the path to the mercurial package that is actually found by
     the current Python interpreter."""
     global _hgpath
     if _hgpath is not None:
         return _hgpath
 
     cmd = '%s -c "import mercurial; print mercurial.__path__[0]"'
     pipe = os.popen(cmd % PYTHON)
     try:
         _hgpath = pipe.read().strip()
     finally:
         pipe.close()
     return _hgpath
 
 def _checkhglib(verb):
     """Ensure that the 'mercurial' package imported by python is
     the one we expect it to be.  If not, print a warning to stderr."""
     expecthg = os.path.join(PYTHONDIR, 'mercurial')
     actualhg = _gethgpath()
     if actualhg != expecthg:
         sys.stderr.write('warning: %s with unexpected mercurial lib: %s\n'
                          '         (expected %s)\n'
                          % (verb, actualhg, expecthg))
 
 def runchildren(options, tests):
     if INST:
         installhg(options)
         _checkhglib("Testing")
 
     optcopy = dict(options.__dict__)
     optcopy['jobs'] = 1
     if optcopy['with_hg'] is None:
         optcopy['with_hg'] = os.path.join(BINDIR, "hg")
     opts = []
     for opt, value in optcopy.iteritems():
         name = '--' + opt.replace('_', '-')
         if value is True:
             opts.append(name)
         elif value is not None:
             opts.append(name + '=' + str(value))
 
     tests.reverse()
     jobs = [[] for j in xrange(options.jobs)]
     while tests:
         for job in jobs:
             if not tests: break
             job.append(tests.pop())
     fps = {}
     for j, job in enumerate(jobs):
         if not job:
             continue
         rfd, wfd = os.pipe()
         childopts = ['--child=%d' % wfd, '--port=%d' % (options.port + j * 3)]
         cmdline = [PYTHON, sys.argv[0]] + opts + childopts + job
         vlog(' '.join(cmdline))
         fps[os.spawnvp(os.P_NOWAIT, cmdline[0], cmdline)] = os.fdopen(rfd, 'r')
         os.close(wfd)
     failures = 0
     tested, skipped, failed = 0, 0, 0
     skips = []
     fails = []
     while fps:
         pid, status = os.wait()
         fp = fps.pop(pid)
         l = fp.read().splitlines()
         test, skip, fail = map(int, l[:3])
         split = -fail or len(l)
         for s in l[3:split]:
             skips.append(s.split(" ", 1))
         for s in l[split:]:
             fails.append(s.split(" ", 1))
         tested += test
         skipped += skip
         failed += fail
         vlog('pid %d exited, status %d' % (pid, status))
         failures |= status
     print
     for s in skips:
         print "Skipped %s: %s" % (s[0], s[1])
     for s in fails:
         print "Failed %s: %s" % (s[0], s[1])
 
     _checkhglib("Tested")
     print "# Ran %d tests, %d skipped, %d failed." % (
         tested, skipped, failed)
     sys.exit(failures != 0)
 
 def runtests(options, tests):
     global DAEMON_PIDS, HGRCPATH
     DAEMON_PIDS = os.environ["DAEMON_PIDS"] = os.path.join(HGTMP, 'daemon.pids')
     HGRCPATH = os.environ["HGRCPATH"] = os.path.join(HGTMP, '.hgrc')
 
     try:
         if INST:
             installhg(options)
             _checkhglib("Testing")
 
         if options.timeout > 0:
             try:
                 signal.signal(signal.SIGALRM, alarmed)
                 vlog('# Running each test with %d second timeout' %
                      options.timeout)
             except AttributeError:
                 print 'WARNING: cannot run tests with timeouts'
                 options.timeout = 0
 
         tested = 0
         failed = 0
         skipped = 0
 
         if options.restart:
             orig = list(tests)
             while tests:
                 if os.path.exists(tests[0] + ".err"):
                     break
                 tests.pop(0)
             if not tests:
                 print "running all tests"
                 tests = orig
 
         skips = []
         fails = []
         for test in tests:
             if options.retest and not os.path.exists(test + ".err"):
                 skipped += 1
                 continue
             ret = runone(options, test, skips, fails)
             if ret is None:
                 skipped += 1
             elif not ret:
                 if options.interactive:
                     print "Accept this change? [n] ",
                     answer = sys.stdin.readline().strip()
                     if answer.lower() in "y yes".split():
                         rename(test + ".err", test + ".out")
                         tested += 1
                         fails.pop()
                         continue
                 failed += 1
                 if options.first:
                     break
             tested += 1
 
         if options.child:
             fp = os.fdopen(options.child, 'w')
             fp.write('%d\n%d\n%d\n' % (tested, skipped, failed))
             for s in skips:
                 fp.write("%s %s\n" % s)
             for s in fails:
                 fp.write("%s %s\n" % s)
             fp.close()
         else:
             print
             for s in skips:
                 print "Skipped %s: %s" % s
             for s in fails:
                 print "Failed %s: %s" % s
             _checkhglib("Tested")
             print "# Ran %d tests, %d skipped, %d failed." % (
                 tested, skipped, failed)
 
         if options.anycoverage:
             outputcoverage(options)
     except KeyboardInterrupt:
         failed = True
         print "\ninterrupted!"
 
     if failed:
         sys.exit(1)
 
 def main():
     (options, args) = parseargs()
     if not options.child:
         os.umask(022)
 
         checktools()
 
     # Reset some environment variables to well-known values so that
     # the tests produce repeatable output.
     os.environ['LANG'] = os.environ['LC_ALL'] = 'C'
     os.environ['TZ'] = 'GMT'
     os.environ["EMAIL"] = "Foo Bar <[e-mail]>"
     os.environ['CDPATH'] = ''
 
     global TESTDIR, HGTMP, INST, BINDIR, PYTHONDIR, COVERAGE_FILE
     TESTDIR = os.environ["TESTDIR"] = os.getcwd()
     HGTMP = os.environ['HGTMP'] = os.path.realpath(tempfile.mkdtemp('', 'hgtests.',
                                                    options.tmpdir))
     DAEMON_PIDS = None
     HGRCPATH = None
 
     os.environ["HGEDITOR"] = sys.executable + ' -c "import sys; sys.exit(0)"'
     os.environ["HGMERGE"] = "internal:merge"
     os.environ["HGUSER"]   = "test"
     os.environ["HGENCODING"] = "ascii"
     os.environ["HGENCODINGMODE"] = "strict"
     os.environ["HGPORT"] = str(options.port)
     os.environ["HGPORT1"] = str(options.port + 1)
     os.environ["HGPORT2"] = str(options.port + 2)
 
     if options.with_hg:
         INST = None
         BINDIR = os.path.dirname(os.path.realpath(options.with_hg))
 
         # This looks redundant with how Python initializes sys.path from
         # the location of the script being executed.  Needed because the
         # "hg" specified by --with-hg is not the only Python script
         # executed in the test suite that needs to import 'mercurial'
         # ... which means it's not really redundant at all.
         PYTHONDIR = BINDIR
     else:
         INST = os.path.join(HGTMP, "install")
         BINDIR = os.environ["BINDIR"] = os.path.join(INST, "bin")
         PYTHONDIR = os.path.join(INST, "lib", "python")
 
     os.environ["BINDIR"] = BINDIR
     os.environ["PYTHON"] = PYTHON
 
     if not options.child:
         path = [BINDIR] + os.environ["PATH"].split(os.pathsep)
         os.environ["PATH"] = os.pathsep.join(path)
 
-        # Deliberately override existing PYTHONPATH: do not want success
-        # to depend on what happens to be in caller's environment.
-        os.environ["PYTHONPATH"] = PYTHONDIR
+        # We have to augment PYTHONPATH, rather than simply replacing
+        # it, in case external libraries are only available via current
+        # PYTHONPATH.  (In particular, the Subversion bindings on OS X
+        # are in /opt/subversion.)
+        os.environ["PYTHONPATH"] = (PYTHONDIR + os.pathsep +
+                                    os.environ.get("PYTHONPATH", ""))
 
     COVERAGE_FILE = os.path.join(TESTDIR, ".coverage")
 
     if len(args) == 0:
         args = os.listdir(".")
         args.sort()
 
     tests = []
     for test in args:
         if (test.startswith("test-") and '~' not in test and
             ('.' not in test or test.endswith('.py') or
              test.endswith('.bat'))):
             tests.append(test)
     if not tests:
         print "# Ran 0 tests, 0 skipped, 0 failed."
         return
 
     vlog("# Using TESTDIR", TESTDIR)
     vlog("# Using HGTMP", HGTMP)
     vlog("# Using PATH", os.environ["PATH"])
     vlog("# Using PYTHONPATH", os.environ["PYTHONPATH"])
 
     try:
         if len(tests) > 1 and options.jobs > 1:
             runchildren(options, tests)
         else:
             runtests(options, tests)
     finally:
         cleanup(options)
 
 main()