cubicweb #674106 OSError: [Errno 12] Cannot allocate memory [rejected]

After an big migration that bloated the python process's memory footprint, I got this traceback on what I presume is the diff of the configuration files at the end.

Traceback (most recent call last):
 File "/usr/lib/python2.5/site-packages/cubicweb/cwctl.py", line 122, in run_arg
   cmdmeth(appid)
 File "/usr/lib/python2.5/site-packages/cubicweb/cwctl.py", line 688, in upgrade_instance
   mih.rewrite_configuration()
 File "/usr/lib/python2.5/site-packages/cubicweb/common/migration.py", line 365, in rewrite_configuration
   show_diffs(configfile, newconfig)
 File "/usr/lib/python2.5/site-packages/cubicweb/toolsutils.py", line 75, in show_diffs
   p_output = os.popen('diff -u %s %s' % (appl_file, ref_file), 'r')
 OSError: [Errno 12] Cannot allocate memory
 instance myinstance not upgraded: [Errno 12] Cannot allocate memory

The server still had swap space available.

prioritynormal
typebug
done in<not specified>
load0.000
load left0.000
closed by<not specified>