[Qemu-devel] Building qemu with old python issue

[Steve Ellcey]

I am building qemu on an old system with python 2.4.3.  The latest checkin:

  commit 9d34158a5af734e8de0b42b0a7228200c426a8d0
  Merge: 8f1ed5f bd80a8a
  Author: Peter Maydell <address@hidden>
  Date:   Mon Sep 7 16:07:47 2015 +0100

    Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20150907' into 
staging

caused my qemu build to fail with:

  File "/scratch/gcc/nightly/src/qemu/scripts/qapi.py", line 947, in cgen
    raw = re.subn("^.", indent + r'\g<0>', raw, 0, re.MULTILINE)
    raw = re.subn("^.", indent + r'\g<0>', raw, 0, re.MULTILINE)
TypeError: subn() : subn() takes at most 4 arguments (5 given)

Now the recent patch did not introduce the use of subn, it just seems
to have changed something so that I call it now whereas before I did not.
The actual use of subn was introduced with this qemu patch:

  commit 77e703b861d34bb2879f3e845482d5cf0a3a0ad1
  Author: Markus Armbruster <address@hidden>
  Date:   Wed Jun 24 19:27:32 2015 +0200

    qapi: Clean up cgen() and mcgen()

It looks like the 5th (optional) argument to subn in python was added
with python 2.7 and I am using python 2.4.3.

Is the use of the 5th argument on subn needed?  And is it intentional
that qemu cannot be built without a python 2.7 or later?

Steve Ellcey
address@hidden