Seems that you have problems connecting to github via https.
While I'm not sure what could cause it and how to fix it, you still can use git with another protocol.
Here's the commands to install homebrew in
/usr/local/ from scratch using
git:// instead of
git init -q
git remote add origin git://github.com/mxcl/homebrew
git fetch origin master:refs/remotes/origin/master -n
git reset --hard origin/master
That should work. Please notice that if you choose to use another directory for homebrew, you probably will have to append its
./bin directory to your environment PATH variable for comfortable usage.