I just released 1.7.7-1. This release fixes a bunch of bugs, some of them freshly introduced with 1.7.6. It also introduces a very few
number of new features.

Most notably it partially reverts a backward incompatibility which affects Cygwin applications which also call native Win32 functions to do part of their job.

Unfortunately this goes hand in hand with a regression, kind of. So far it was possible in Cygwin 1.7.x to remove a directory which was the current working directory (CWD) of another Cygwin process, or even the CWD of the process itself. This Linux-like feature had to be dropped, because the implementation could result in strange handle problems on Vista and later, and the workaround in 1.7.6 introduced more problems than anticipated.

So we're back to Win32-like behaviour, which is, rmdir returns with "Device or resource busy" when trying to remove a directory which is CWD of a Cygwin process. Fortunately this behaviour is covered and explicitely allowed by the POSIX standard, so we're still on firm ground, standards-wise.

I think this goes without saying, but please have another look into the documentation at http://cygwin.com/cygwin-ug-net/cygwin-ug-net.html. It contains a couple of improvements and the description for new features and changes from old behaviour.