4b7afcc3553c149261f457c3de88ff9d5458a3f6 is the first bad commit
commit 4b7afcc3553c149261f457c3de88ff9d5458a3f6
Date: Sat Jun 11 12:35:13 2011 -0500
Create Base class for Environment and Index
:040000 040000 5423b6f2fc31d6834207ada0252fa2e61086be74 0b0396b560ccb5947bf5c47668e6629c7c60e525 M lib
:040000 040000 112d4ec7a3a494c29693546cc19abb2a1ba4e475 8fe7693a9440ae64fd7ae79dc37f7cf5e4607ae4 M test
I'm not quite sure how to narrow the problem down further. There were quite a lot of changes in that commit.