# HG changeset patch
# User Bryan O'Sullivan <bryano@fb.com>
# Date 1352829326 28800
# Node ID 65a46635fb3167f374f0b187e0b432945e8e9b10
# Parent  2631b3576a3360477fb040f1000cdfb7debdbc91
setup: print subprocess stderr if there is any

I just spent 1.5 days trying to debug a failing buildbot because
setup.py was silently dropping the errors that were being printed
by in-place hg.

diff -r 2631b3576a33 -r 65a46635fb31 setup.py
--- a/setup.py	Sat Nov 10 11:37:41 2012 -0800
+++ b/setup.py	Tue Nov 13 09:55:26 2012 -0800
@@ -151,6 +151,8 @@
            if not e.startswith(b('Not trusting file')) \
               and not e.startswith(b('warning: Not importing'))]
     if err:
+        print >> sys.stderr, "stderr from '%s':" % (' '.join(cmd))
+        print >> sys.stderr, '\n'.join(['  ' + e for e in err])
         return ''
     return out