As I asked and answered here, I found that running \'sudo lein deps causes some problem that forces me to run \'sudo lein swank\', which is
yes removing .m2 and then lein self-install
should fix this :)
when you can sudo lein ... it created files in .m2 owned by root so removing these and then recreating them as the proper user (you) should fix it. you could perhaps also just change the user on them back to yourself.
chown username:users ~/.m2/*