Somebody else had this same issue (http://www.minecraftforge.net/forum/index.php?topic=17247.0), but they were not given what appears to be any useful advice.
Here is my log:
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http://mcp.ocean-labs.de/
Searge, ProfMobius, Fesh0r,
R4wk, ZeuX, IngisKahn
MCP Data version : unknown
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:downloadMcpTools UP-TO-DATE
:extractUserDev
:genSrgs UP-TO-DATE
:downloadClient SKIPPED
:downloadServer SKIPPED
:mergeJars SKIPPED
:deobfuscateJar UP-TO-DATE
:decompile SKIPPED
:doFmlPatches SKIPPED
:addFmlSources UP-TO-DATE
:remapJar SKIPPED
:doForgePatches
Patching failed: net/minecraft/client/renderer/RenderBlocks.java Cannot find hunk target
Hunk 6 failed! Cannot find hunk target
Hunk 10 failed! Cannot find hunk target
Patching failed: net/minecraft/client/renderer/entity/RenderItem.java Cannot find hunk target
Hunk 11 failed! Cannot find hunk target
Hunk 12 failed! Cannot find hunk target
:doForgePatches FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':doForgePatches'.
> Could not call EditJarTask.doTask() on task ':doForgePatches'
Anybody know how to fix this?