This or some variant also shows up with scons
(http://scons.tigris.org/issues/show_bug.cgi?id=1839) leading to some
nasty intermittent build failures.  Neal may remember how we addressed
this for a Process class in a past life.  Basically it's OK to collect
all the child exit codes if you record the results and return them when
requested. This would mean that waitpid and the like would have to check
a cached list of PIDs and exit statuses before actually waiting.  Don't
know if that's possible/any help in this case or not...

Traceback (most recent call last):
  File "/usr/lib/scons-0.97.0d20070918/SCons/Taskmaster.py", line 194,
in execute
    self.targets[0].build()
  File "/usr/lib/scons-0.97.0d20070918/SCons/Node/__init__.py", line
365, in build
    stat = apply(executor, (self,), kw)
  File "/usr/lib/scons-0.97.0d20070918/SCons/Executor.py", line 139, in
__call__
    return self.do_execute(target, kw)
  File "/usr/lib/scons-0.97.0d20070918/SCons/Executor.py", line 129, in
do_execute
    status = apply(act, (self.targets, self.sources, env), kw)
  File "/usr/lib/scons-0.97.0d20070918/SCons/Action.py", line 332, in
__call__
    stat = self.execute(target, source, env)
  File "/usr/lib/scons-0.97.0d20070918/SCons/Action.py", line 479, in
execute
    result = spawn(shell, escape, cmd_line[0], cmd_line, ENV)
  File "/usr/lib/scons-0.97.0d20070918/SCons/Platform/posix.py", line
104, in spawnvpe_spawn
    return exec_spawnvpe([sh, '-c', string.join(args)], env)
  File "/usr/lib/scons-0.97.0d20070918/SCons/Platform/posix.py", line
68, in exec_spawnvpe
    stat = os.spawnvpe(os.P_WAIT, l[0], l, env)
  File "/sw/pkgs/python-2.3.5_00/lib/python2.3/os.py", line 553, in spawnvpe
    return _spawnvef(mode, file, args, env, execvpe)
  File "/sw/pkgs/python-2.3.5_00/lib/python2.3/os.py", line 504, in
_spawnvef
    wpid, sts = waitpid(pid, 0)
OSError: [Errno 10] No child processes
scons: building terminated because of errors.