diff --git a/git-remote-testgit.py b/git-remote-testgit.py
index 92539222c..df9d512f1 100644
--- a/git-remote-testgit.py
+++ b/git-remote-testgit.py
@@ -1,6 +1,12 @@
 #!/usr/bin/env python
 
-import hashlib
+# hashlib is only available in python >= 2.5
+try:
+    import hashlib
+    _digest = hashlib.sha1
+except ImportError:
+    import sha
+    _digest = sha.new
 import sys
 import os
 sys.path.insert(0, os.getenv("GITPYTHONLIB","."))
@@ -19,7 +25,7 @@ def get_repo(alias, url):
     repo.get_revs()
     repo.get_head()
 
-    hasher = hashlib.sha1()
+    hasher = _digest()
     hasher.update(repo.path)
     repo.hash = hasher.hexdigest()
 
@@ -133,7 +139,10 @@ def do_export(repo, args):
 
     path = os.path.join(dirname, 'testgit.marks')
     print path
-    print path if os.path.exists(path) else ""
+    if os.path.exists(path):
+        print path
+    else:
+        print ""
     sys.stdout.flush()
 
     update_local_repo(repo)
diff --git a/git_remote_helpers/git/exporter.py b/git_remote_helpers/git/exporter.py
index dfaab00b5..f40f9d6a2 100644
--- a/git_remote_helpers/git/exporter.py
+++ b/git_remote_helpers/git/exporter.py
@@ -48,4 +48,6 @@ def export_repo(self, base):
 
         args = ["sed", "s_refs/heads/_" + self.repo.prefix + "_g"]
 
-        subprocess.check_call(args, stdin=p1.stdout)
+        child = subprocess.Popen(args, stdin=p1.stdout)
+        if child.wait() != 0:
+            raise CalledProcessError
diff --git a/git_remote_helpers/git/importer.py b/git_remote_helpers/git/importer.py
index af2919d92..70a712729 100644
--- a/git_remote_helpers/git/importer.py
+++ b/git_remote_helpers/git/importer.py
@@ -35,4 +35,6 @@ def do_import(self, base):
         if os.path.exists(path):
             args.append("--import-marks=" + path)
 
-        subprocess.check_call(args)
+        child = subprocess.Popen(args)
+        if child.wait() != 0:
+            raise CalledProcessError
diff --git a/git_remote_helpers/git/non_local.py b/git_remote_helpers/git/non_local.py
index d75ef8f21..f27389bb9 100644
--- a/git_remote_helpers/git/non_local.py
+++ b/git_remote_helpers/git/non_local.py
@@ -29,7 +29,9 @@ def clone(self, base):
         os.makedirs(path)
         args = ["git", "clone", "--bare", "--quiet", self.repo.gitpath, path]
 
-        subprocess.check_call(args)
+        child = subprocess.Popen(args)
+        if child.wait() != 0:
+            raise CalledProcessError
 
         return path
 
@@ -43,10 +45,14 @@ def update(self, base):
             die("could not find repo at %s", path)
 
         args = ["git", "--git-dir=" + path, "fetch", "--quiet", self.repo.gitpath]
-        subprocess.check_call(args)
+        child = subprocess.Popen(args)
+        if child.wait() != 0:
+            raise CalledProcessError
 
         args = ["git", "--git-dir=" + path, "update-ref", "refs/heads/master", "FETCH_HEAD"]
-        subprocess.check_call(args)
+        child = subprocess.Popen(args)
+        if child.wait() != 0:
+            raise CalledProcessError
 
     def push(self, base):
         """Pushes from the non-local repo to base.
@@ -58,4 +64,6 @@ def push(self, base):
             die("could not find repo at %s", path)
 
         args = ["git", "--git-dir=" + path, "push", "--quiet", self.repo.gitpath]
-        subprocess.check_call(args)
+        child = subprocess.Popen(args)
+        if child.wait() != 0:
+            raise CalledProcessError
diff --git a/git_remote_helpers/git/repo.py b/git_remote_helpers/git/repo.py
index 82d5f78c7..58e1cdb56 100644
--- a/git_remote_helpers/git/repo.py
+++ b/git_remote_helpers/git/repo.py
@@ -19,7 +19,10 @@ def is_remote(url):
 
     prefixes = ["http", "file", "git"]
 
-    return any(url.startswith(i) for i in prefixes)
+    for prefix in prefixes:
+        if url.startswith(prefix):
+            return True
+    return False
 
 class GitRepo(object):
     """Repo object representing a repo.
@@ -50,7 +53,9 @@ def get_revs(self):
         path = ".cached_revs"
         ofile = open(path, "w")
 
-        subprocess.check_call(args, stdout=ofile)
+        child = subprocess.Popen(args, stdout=ofile)
+        if child.wait() != 0:
+            raise CalledProcessError
         output = open(path).readlines()
         self.revmap = dict(sanitize(i) for i in output)
         if "HEAD" in self.revmap:
diff --git a/t/t5800-remote-helpers.sh b/t/t5800-remote-helpers.sh
index 22c7df47f..4ee7b65ce 100755
--- a/t/t5800-remote-helpers.sh
+++ b/t/t5800-remote-helpers.sh
@@ -9,13 +9,13 @@ test_description='Test remote-helper import and export commands'
 
 if test_have_prereq PYTHON && "$PYTHON_PATH" -c '
 import sys
-if sys.hexversion < 0x02050000:
+if sys.hexversion < 0x02040000:
     sys.exit(1)
 '
 then
 	:
 else
-	say 'skipping git remote-testgit tests: requires Python 2.5 or newer'
+	say 'skipping git remote-testgit tests: requires Python 2.4 or newer'
 	test_done
 fi