[PATCH] setup.py: do not install c extensions on pypy

[Joan Massich]

# HG changeset patch
# User Joan Massich <mailsik at gmail.com>
# Date 1424616036 -3600
#      Sun Feb 22 15:40:36 2015 +0100
# Node ID 38aba71094d3f8fb7823731cce21cc6bbc784f74
# Parent  e7785573a4af258101d0cc0b0947a6de65273096
setup.py: do not install c extensions on pypy

These extensions are slower on pypy because pypy has a JIT compiler.
And also, they often do not compile (it depends on the pypy configuration).

diff -r e7785573a4af -r 38aba71094d3 setup.py
--- a/setup.py	Wed Feb 18 16:45:16 2015 -0800
+++ b/setup.py	Sun Feb 22 15:40:36 2015 +0100
@@ -63,6 +63,8 @@
         raise SystemExit(
             "Couldn't import standard bz2 (incomplete Python install).")
 
+ispypy = "PyPy" in sys.version
+
 import os, stat, subprocess, time
 import re
 import shutil
@@ -276,7 +278,7 @@
 
 
 class hgdist(Distribution):
-    pure = 0
+    pure = ispypy
 
     global_options = Distribution.global_options + \
                      [('pure', None, "use pure (slow) Python "