tests/hghave.py

--- a/tests/hghave.py	Fri Jan 24 14:11:43 2020 -0800
+++ b/tests/hghave.py	Fri Feb 07 15:55:21 2020 +0100
@@ -307,13 +307,23 @@
         return False
 
 
-def gethgversion():
+def _gethgversion():
     m = matchoutput('hg --version --quiet 2>&1', br'(\d+)\.(\d+)')
     if not m:
         return (0, 0)
     return (int(m.group(1)), int(m.group(2)))
 
 
+_hgversion = None
+
+
+def gethgversion():
+    global _hgversion
+    if _hgversion is None:
+        _hgversion = _gethgversion()
+    return _hgversion
+
+
 @checkvers(
     "hg", "Mercurial >= %s", list([(1.0 * x) / 10 for x in range(9, 99)])
 )