cannot clone this repo

[lovettchris]

Getting a weird error:

(ell) C:\temp\mathlib_docs>git checkout master
error: invalid path 'docs/find/con.Inf_def/index.html'
error: invalid path 'docs/find/con.Inf_def/src/index.html'
error: invalid path 'docs/find/con.Inf_to_setoid/index.html'
error: invalid path 'docs/find/con.Inf_to_setoid/src/index.html'
error: invalid path 'docs/find/con.Sup_def/index.html'
error: invalid path 'docs/find/con.Sup_def/src/index.html'
...

[jcommelin]

I don't know anything about windows filenames: could it be an issue that a . in a directory name is not allowed?