--- a/tests/run-tests.py	Fri Apr 08 18:35:49 2016 +0000
+++ b/tests/run-tests.py	Thu Apr 07 11:11:55 2016 +0000
@@ -2314,7 +2314,7 @@
         This will also configure hg with the appropriate testing settings.
         """
         vlog("# Performing temporary installation of HG")
-        installerrs = os.path.join(b"tests", b"install.err")
+        installerrs = os.path.join(self._hgtmp, b"install.err")
         compiler = ''
         if self.options.compiler:
             compiler = '--compiler ' + self.options.compiler