Re: Git commit error: fatal: Repository has been updated, but unable to write new_index file.

fatal: Repository has been updated, but unable to write new_index
file. Check that disk is not full or quota is not exceeded, and then
"git reset HEAD" to recover.

Here is the command which IDE executes to make a commit:

# git commit --only -F<message file>  -- <several files chosen to
commit>

I can confirm this issue. I saw this error more than once. And I'm 
working with cygwin Git on the command line - but having an IDE (VS in 
this case) opened in parallel.

I don't think the issue is about two parallel Git operations in 
parallel. I only started one. But more that some file of the working 
copy is in access. And Git seems to be much more sensible about those 
than i.e. subversion. (No file was "locked")

Sorry - but I cannot tell anything more except that I've experienced 
this issue too. Maybe this is a  windows specific issue? As a windows 
user I had some of them...