My git-n00bness obviously inhibited me a bit here, but I was today in the situation of creating a new location from which to blog (a hosted VM, more about which in a separate post).
So I ran git clone https://github.com/agam/agam.github.io.git, which gave me the master branch.
But I also needed the source branch. So I naively ran git pull origin source, which resulted in ... a merge conflict on index.html?! WTF?
I 'fixed' that by making index.html empty. But rake generate failed with weird errors and git branch still shows only source. So what was wrong?
This stackoverflow post had a possible answer on how to proceed.
I tried running git checkout origin/source but that brought on the dreaded experimental HEAD error message.
No luck. Then I came across this post which seemed to describe a similar situation (I crossed my fingers that I hadn't already screwed up my repo).
Aha! (I won't forget it now). You're supposed to specify the branch name when you check out!
So I rm -rfed my setup, then ran the following:
git clone -b source https://github.com/agam/agam.github.io.git
cd agam.github.io
git clone https://github.com/agam/agam.github.io.git _deploy
After this, rake new_post worked as expected, but rake generate still failed on some plugin error about an "invalid byte sequence".
That led me to this gist. export LANG=en_US.utf-8 fixed the generate problem.
And then rake deploy worked as expected, so yay!