--- a/hgext3rd/evolve/obscache.py	Thu May 18 22:12:05 2017 +0200
+++ b/hgext3rd/evolve/obscache.py	Thu May 18 22:42:13 2017 +0200
@@ -7,16 +7,19 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
+import errno
 import hashlib
+import os
 import struct
+import time
 import weakref
-import errno
 
 from mercurial import (
     error,
     localrepo,
     obsolete,
     phases,
+    pycompat,
     node,
     util,
 )
@@ -29,6 +32,17 @@
 
 eh = exthelper.exthelper()
 
+# prior to hg-4.2 there are not util.timer
+if util.safehasattr(util, 'timer'):
+    timer = util.timer
+elif util.safehasattr(time, "perf_counter"):
+    timer = time.perf_counter
+elif getattr(pycompat, 'osname', os.name) == 'nt':
+    timer = time.clock
+else:
+    timer = time.time
+
+
 try:
     obsstorefilecache = localrepo.localrepository.obsstore
 except AttributeError:
@@ -209,9 +223,9 @@
             repo.ui.log('evoext-cache', 'strip detected, %s cache reset\n' % self._cachename)
             self.clear(reset=True)
 
-        starttime = util.timer()
+        starttime = timer()
         self._updatefrom(repo, revs, obsmarkers)
-        duration = util.timer() - starttime
+        duration = timer() - starttime
         repo.ui.log('evoext-cache', 'updated %s in %.4f seconds (%sr, %so)\n',
                     self._cachename, duration, len(revs), len(obsmarkers))
 

--- a/hgext3rd/evolve/obsdiscovery.py	Thu May 18 22:12:05 2017 +0200
+++ b/hgext3rd/evolve/obsdiscovery.py	Thu May 18 22:42:13 2017 +0200
@@ -24,8 +24,10 @@
 
 import hashlib
 import heapq
+import os
 import sqlite3
 import struct
+import time
 import weakref
 
 from mercurial import (
@@ -36,6 +38,7 @@
     localrepo,
     node,
     obsolete,
+    pycompat,
     scmutil,
     setdiscovery,
     util,
@@ -51,6 +54,16 @@
     stablerange,
 )
 
+# prior to hg-4.2 there are not util.timer
+if util.safehasattr(util, 'timer'):
+    timer = util.timer
+elif util.safehasattr(time, "perf_counter"):
+    timer = time.perf_counter
+elif getattr(pycompat, 'osname', os.name) == 'nt':
+    timer = time.clock
+else:
+    timer = time.time
+
 _pack = struct.pack
 _unpack = struct.unpack
 _calcsize = struct.calcsize
@@ -215,7 +228,7 @@
                      initialsamplesize=100,
                      fullsamplesize=200):
     missing = set()
-    starttime = util.timer()
+    starttime = timer()
 
     heads = local.revs('heads(%ld)', probeset)
     local.stablerange.warmup(local)
@@ -303,7 +316,7 @@
         ui.progress(_("comparing obsmarker with other"), querycount)
     ui.progress(_("comparing obsmarker with other"), None)
     local.obsstore.rangeobshashcache.save(local)
-    duration = util.timer() - starttime
+    duration = timer() - starttime
     logmsg = ('obsdiscovery, %d/%d mismatch'
               ' - %d obshashrange queries in %.4f seconds\n')
     logmsg %= (len(missing), len(probeset), querycount, duration)

--- a/hgext3rd/evolve/stablerange.py	Thu May 18 22:12:05 2017 +0200
+++ b/hgext3rd/evolve/stablerange.py	Thu May 18 22:42:13 2017 +0200
@@ -10,7 +10,9 @@
 import collections
 import heapq
 import math
+import os
 import sqlite3
+import time
 import weakref
 
 from mercurial import (
@@ -19,6 +21,7 @@
     error,
     localrepo,
     node as nodemod,
+    pycompat,
     scmutil,
     util,
 )
@@ -31,6 +34,16 @@
 
 eh = exthelper.exthelper()
 
+# prior to hg-4.2 there are not util.timer
+if util.safehasattr(util, 'timer'):
+    timer = util.timer
+elif util.safehasattr(time, "perf_counter"):
+    timer = time.perf_counter
+elif getattr(pycompat, 'osname', os.name) == 'nt':
+    timer = time.clock
+else:
+    timer = time.time
+
 ##################################
 ### Stable topological sorting ###
 ##################################
@@ -263,7 +276,7 @@
         #
         # we use the revnumber as an approximation for depth
         ui = repo.ui
-        starttime = util.timer()
+        starttime = timer()
 
         if upto is None:
             upto = len(cl) - 1
@@ -309,7 +322,7 @@
         self._tiprev = upto
         self._tipnode = cl.node(upto)
 
-        duration = util.timer() - starttime
+        duration = timer() - starttime
         repo.ui.log('evoext-cache', 'updated stablerange cache in %.4f seconds\n',
                     duration)