Using my own implementation of RFC 6979 on top of warner's ECDSA code, I generated a few test vectors. slush's patch matches up perfectly!
For future reference, here are the test vectors:
# Test Vectors for RFC 6979 ECDSA, secp256k1, SHA-256
# (private key, message, expected k, expected signature)
test_vectors = [
(0x1, "Satoshi Nakamoto", 0x8F8A276C19F4149656B280621E358CCE24F5F52542772691EE69063B74F15D15, "934b1ea10a4b3c1757e2b0c017d0b6143ce3c9a7e6a4a49860d7a6ab210ee3d8dbbd3162d46e9f9bef7feb87c16dc13b4f6568a87f4e83f728e2443ba586675c"),
(0x1, "All those moments will be lost in time, like tears in rain. Time to die...", 0x38AA22D72376B4DBC472E06C3BA403EE0A394DA63FC58D88686C611ABA98D6B3, "8600dbd41e348fe5c9465ab92d23e3db8b98b873beecd930736488696438cb6bab8019bbd8b6924cc4099fe625340ffb1eaac34bf4477daa39d0835429094520"),
(0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364140, "Satoshi Nakamoto", 0x33A19B60E25FB6F4435AF53A3D42D493644827367E6453928554F43E49AA6F90, "fd567d121db66e382991534ada77a6bd3106f0a1098c231e47993447cd6af2d094c632f14e4379fc1ea610a3df5a375152549736425ee17cebe10abbc2a2826c"),
(0xf8b8af8ce3c7cca5e300d33939540c10d45ce001b8f252bfbc57ba0342904181, "Alan Turing", 0x525A82B70E67874398067543FD84C83D30C175FDC45FDEEE082FE13B1D7CFDF1, "7063ae83e7f62bbb171798131b4a0564b956930092b33b07b395615d9ec7e15ca72033e1ff5ca1ea8d0c99001cb45f0272d3be7525d3049c0d9e98dc7582b857")
]