Restrict workaround to Windows only.

Author: notoraptor

versioneer.py

@@ -1046,9 +1046,15 @@ def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
 
     # if there is a tag matching tag_prefix, this yields TAG-NUM-gHEX[-dirty]
     # if there isn't one, this yields HEX[-dirty] (no NUM)
-    describe_out, rc = run_command(GITS, ["describe", "--tags", "--dirty",
-                                          "--always", "--long"],
-                                   cwd=root)
+    if sys.platform == 'win32':
+        describe_out, rc = run_command(GITS, ["describe", "--tags", "--dirty",
+                                              "--always", "--long"],
+                                       cwd=root)
+    else:
+        describe_out, rc = run_command(GITS, ["describe", "--tags", "--dirty",
+                                              "--always", "--long",
+                                              "--match", "%s*" % tag_prefix],
+                                       cwd=root)
     # --long was added in git-1.5.5
     if describe_out is None:
         raise NotThisMethod("'git describe' failed")