"warning: unable to unlink" when dealing with git submodules

I installed a submodule on branch try-submodules when trying to checkout the master branch (which had no submodules), I get the following w开发者_运维问答arning:

warning: unable to unlink public/docs/blueprint: Operation not permitted Switched to branch 'master'

Browsing the file directory, I can see that everything checked out just fine EXCEPT my blueprint subdirectory still exists, even though it is not present in the master branch.

I've found a few discussions of this problem: http://cygwin.com/ml/cygwin/2009-11/msg00756.html, but no solutions.

Any ideas?

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i have the same problem, as a workaround you can remove the submodule dir with 'rm -rf' (force is important here) and checkout the branch again