/bin/uname: Permission denied

Drush is only calling uname to see if you are running on Cygwin, which you are not. As a workaround to this problem, you could make sure that $HOME/bin occurs in your PATH before uname does, and make your own uname script that does nothing.

e.g.: in $HOME/bin/uname

#!/bin/bash

exit 0

Don't forget to chmod +x your uname script.

I'm also experiencing this in a shared hosting with chrooted ssh access. I think this is a increasingly common scenario.

The warning can be avoid easily if we check the user has rights to execute uname.

I don't have a restricted shared host environment to test #4 on, but it works fine on normal environments, and looks like a good thing to do in general.

Changing classification to feature request - support restricted environments with no access to uname.

Committed to both branches.