@SvenDowideit That doesn't work, however, `mktemp -d -t $($TMPDIR)dockerdl` worked just fine:
```
$ mktemp -d -t $($TMPDIR)dockerdl
/tmp/dockerdl.1gURS8Wb
```
Here are the options mktemp accepts on OS X:
```
usage: mktemp [-d] [-q] [-t prefix] [-u] template ...
       mktemp [-d] [-q] [-u] -t prefix
```