Minor Description
Let /foo be a directory in HDFS (issue does not occur with files) and /bar be a local dir. Do something like:
$ chmod u-w /bar
$ hadoop -get /foo/myfile /bar
copyToLocal: Permission denied # correctly tells me permission is denied
$ hadoop -get /foo /bar
copyToLocal: null
$ hadoop -get /foo/ /bar
copyToLocal: No such file or directory
I've been banging my head for a bit trying to figure out why hadoop thinks my directory doesn't exist, but it turns out the problem was just with my local permissions. The "Permission denied" error would've been a lot nicer to get.