added logic to prevent directory creation collisions

Author: poldrack

nipype/pipeline/engine/utils.py

@@ -1056,9 +1056,15 @@ def make_output_dir(outdir):
     outdir : output directory to create
 
     """
-    if not os.path.exists(os.path.abspath(outdir)):
-        logger.debug("Creating %s" % outdir)
-        os.makedirs(outdir)
+    # this odd approach deals with concurrent directory cureation
+    try:
+        if not os.path.exists(os.path.abspath(outdir)):
+            logger.debug("Creating %s" % outdir)
+            os.makedirs(outdir)
+    except OSError:
+            logger.debug("Problem creating %s" % outdir)
+            if not os.path.exists(outdir):
+               raise OSError('Could not create %s'%outdir)
     return outdir