For what it's worth I get the same error.
Of course you can do a git clone the regular way (without using http):
git clone git://svolli.org/software/tinycore/.git
But not if you happen to try it behind the firewall of your corporate overloard, which is I suppose why you're trying git over http in the first place.
So it looks like either you propose that the TC git binary should have a curl dependency, or that we have two TC git packages.
Both seem reasonable, but I'd prefer the latter. curl is not too big (164K), though it depends on openssl (900K).