Re: Commit cce8d6fdb introduces file t/t5100/nul, git tree is now incompatible with Cygwin (and probably Windows)

Johannes Schindelin <Johannes.Schindelin <at> gmx.de> writes:

On Mon, 26 May 2008, Mark Levedahl wrote:

quoted

Beginning with the referenced commit, the git project cannot be checked 
out on Cygwin (and I assume cannot be checked out on Windows using 
msysgit, though I have not verified this) as this commit introduces the 
file "t/5100/nul." On Windows, the file name "nul" is reserved, 
regardless of path, and cannot be created or deleted. It serves 
essentially the same function as /dev/null.

Even when referencing the full (or a relative) path?  That's bad!

Yes.  And it is not limited to the case-insensitive name NUL; it also covers
names like "aux".  See the very last paragraph in this section:
http://www.gnu.org/software/autoconf/manual/html_node/File-System-Conventions.html#File-System-Conventions

This will affect all versions of MSYS.  However, with cygwin 1.5.x, you can use
the workaround of a managed mount which intentionally (and transparently) munges
such invalid file names so that you can appear to name a file "nul" in spite of
Windows (at the expense of making an already short PATH_MAX of 256 even
shorter).  And if you are willing to experiment with the (still-in-development)
cygwin 1.7.0, this munging is done without even needing a managed mount and
without any penalty to the larger PATH_MAX of 4k.

At any rate, I agree with your patch to rename the file, as well as with your
aversion to rewriting history just so that a checkout on MSYS or a non-managed
mount on older cygwin can do a 'git bisect' that hits the small window of
commits with an invalid tree.

-- 
Eric Blake