How can I brew link a specific version?

Question

I have a few kegs of the same package in /usr/local/Cellar/libfoo like /usr/local/Cellar/libfoo/1.0.1, /usr/local/Cellar/libfoo/HEAD a

Answer 1

I asked in #machomebrew and learned that you can switch between versions using brew switch.

$ brew switch libfoo mycopy 

to get version mycopy of libfoo.