Add a new --debug-pids option.

This makes the helpers.* log functions prepend getpid() to each line, so you
can see which pid did what.

helpers.py

@@ -35,8 +35,10 @@ def mkdirp(d, mode=None):
 
 def log_(s):
     sys.stdout.flush()
-    sys.stderr.write(s)
-    #sys.stderr.write('%d %s' % (os.getpid(), s))
+    if vars.DEBUG_PIDS:
+        sys.stderr.write('%d %s' % (os.getpid(), s))
+    else:
+        sys.stderr.write(s)
     sys.stderr.flush()
 
 

redo.py

@@ -12,6 +12,7 @@ x,xtrace   print commands as they are executed (variables expanded)
 k,keep-going  keep going as long as possible even if some targets fail
 shuffle    randomize the build order to find dependency bugs
 debug-locks  print messages about file locking (useful for debugging)
+debug-pids   print process ids as part of log messages (useful for debugging)
 """
 o = options.Options('redo', optspec)
 (opt, flags, extra) = o.parse(sys.argv[1:])
@@ -30,6 +31,8 @@ if opt.shuffle:
     os.environ['REDO_SHUFFLE'] = '1'
 if opt.debug_locks:
     os.environ['REDO_DEBUG_LOCKS'] = '1'
+if opt.debug_pids:
+    os.environ['REDO_DEBUG_PIDS'] = '1'
 
 is_root = not os.environ.get('REDO', '')
 

vars.py

@@ -6,6 +6,7 @@ TARGET = os.environ.get('REDO_TARGET', '')
 DEPTH = os.environ.get('REDO_DEPTH', '')
 DEBUG = atoi.atoi(os.environ.get('REDO_DEBUG', ''))
 DEBUG_LOCKS = os.environ.get('REDO_DEBUG_LOCKS', '') and 1 or 0
+DEBUG_PIDS = os.environ.get('REDO_DEBUG_PIDS', '') and 1 or 0
 VERBOSE = os.environ.get('REDO_VERBOSE', '') and 1 or 0
 XTRACE = os.environ.get('REDO_XTRACE', '') and 1 or 0
 KEEP_GOING = os.environ.get('REDO_KEEP_GOING', '') and 1 or 0