I haven't got to the root cause of this, but I have got a workaround.
I manually downloaded git2_git.yoctoproject.org.linux-yocto-3.10.git.tar.gz and copied it into build/downloads, and did 'touch' on build/downloads/git2_git.yoctoproject.org.linux-yocto-3.10.git.tar.gz.done
Then when I did a bitbake linux-yocto, it fetched all the requirements and built the kernel fine.
I think it's something to do with my linux machine, so I'll mark this as the answer for now. If anyone finds the root cause, please let me know
bitbake edison-image worked fine for me - with a bigger rootfs, more functionality for busybox, ...
image boots fine
Looks like there was a broken tarball + broken git on the Yocto side, which caused that. Details + possible workaround for the future is here: https://communities.intel.com/message/259362#259362
I guess in your case mhahn you had a download directory separated and populated by previous builds, so it worked (same as in my case until I cleared the cache).
Excellent Alex. Thanks for that.
you are right: I have my own git where I put the new recipes on top. I ran bitbake cleansstate before but haven't flushed the cache directory.