diff --git a/sphinx_multiversion/git.py b/sphinx_multiversion/git.py
index 6ee52d8e..57c5f0fc 100644
--- a/sphinx_multiversion/git.py
+++ b/sphinx_multiversion/git.py
@@ -7,6 +7,7 @@
 import subprocess
 import tarfile
 import tempfile
+import shutil
 
 GitRef = collections.namedtuple(
     "VersionRef",
@@ -154,17 +155,10 @@ def file_exists(gitroot, refname, filename):
 
 
 def copy_tree(gitroot, src, dst, reference, sourcepath="."):
-    with tempfile.SpooledTemporaryFile() as fp:
-        cmd = (
-            "git",
-            "archive",
-            "--format",
-            "tar",
-            reference.commit,
-            "--",
-            sourcepath,
-        )
-        subprocess.check_call(cmd, cwd=gitroot, stdout=fp)
-        fp.seek(0)
-        with tarfile.TarFile(fileobj=fp) as tarfp:
-            tarfp.extractall(dst)
+    try:
+        shutil.copytree(gitroot, dst)
+    except OSError as e:
+        if e.errno == 17:  # already copied
+            return
+        raise
+    subprocess.call(("git", "checkout", "-f", reference.commit), cwd=dst)
diff --git a/sphinx_multiversion/main.py b/sphinx_multiversion/main.py
index 9870b314..26777ce2 100644
--- a/sphinx_multiversion/main.py
+++ b/sphinx_multiversion/main.py
@@ -229,11 +229,12 @@ def main(argv=None):
             repopath = os.path.join(tmp, gitref.commit)
             try:
                 git.copy_tree(str(gitroot), gitroot.as_uri(), repopath, gitref)
-            except (OSError, subprocess.CalledProcessError):
+            except (OSError, subprocess.CalledProcessError) as e:
                 logger.error(
-                    "Failed to copy git tree for %s to %s",
+                    "Failed to copy git tree for %s to %s:\n%s",
                     gitref.refname,
                     repopath,
+                    e,
                 )
                 continue