[cmake-developers] cmake -E tar not working correctly with xz-compressed tarballs on MSYS

[Brad King]

On 07/21/2013 04:19 PM, Alan W. Irwin wrote:
> So on MSYS platforms the command-line tools
> are working fine for manipulating xz-compressed tarballs, but
> 
> cmake -E tar xfz test.tar.xz
> 
> fails (and also appears to be using the unxz command-line tool
> that is not correctly finding the xz-compressed tarball).
> 
> I suspect this is a trivial issue since the xz-related command-line
> tools all work on MSYS, but as always the difficult thing to do with
> CMake is to find where the issue is occurring.  I starting looking in
> Utilities/cmlibarchive/libarchive, but any additional guidance would
> be appreciated.

CMake's build of libarchive does not enable built-in lzma support.
Libarchive responds by trying to run a command-line tool to handle
the data, probably "xz" in this case.  Something about the MSYS
xz trying to run from inside a CMake process environment may cause
the problem.

-Brad