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

[Alan W. Irwin]

ping.

In sum this "cmake -E tar" issue for *.tar.xz files needs confirmation
for MSYS on the Microsoft version of Windows.  I am pretty sure this
is a simple issue since under MSYS handling of *.tar.xz files is
straightforward from the command line, and my understanding is that
libarchive drops back to the command line when necessary.  However, to
help me generate the appropriate cmake patch I need some further
guidance to where in Utilities/cmlibarchive/libarchive I should be
looking.

Alan

On 2013-07-21 13:19-0700 Alan W. Irwin wrote:

> I created an xz-compressed test tarball on Linux using the J option
>
> tar Jcf test.tar.xz ...
>
> On Linux,
>
> cmake -E tar xfz test.tar.xz
>
> unpacks that tarball without issue.
>
> For MSYS (on a Wine-1.6-rc4 platform), that same command hangs
> indefinitely.  Wine often does not respond well to ordinary errors so
> I used ctrl-C to get out of the hang, and the following message
> was displayed on the command line:
>
> unxz: (stdin): File format not recognized
>
> To remove the Wine uncertainty could someone attempt
> a similar MSYS experiment on the Microsoft version of
> Windows?
>
> However, assuming that verification succeeds, then
> that error message is only delivered if you attempt to do something
> like (under MSYS)
>
> bash.exe-3.1$ cat non-tar.xz_file |unxz -c > test_file
>
> so I assume that is what cmake is trying to do, and there is some
> issue accessing the correct file.
>
> For example, if I execute (under MSYS)
>
> bash.exe-3.1$ cat test.tar.xz |unxz -c >test2.tar
>
> the resulting tarball, test2.tar is fine.
>
> Also, you can create and also unpack xz-compressed tarballs under
> MSYS using the J option.
>
> 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.
>
> Note, the above MSYS tests were done using the Windows binary version
> of cmake-2.8.11.2 that was obtained by
>
> wget "http://www.cmake.org/files/v2.8/cmake-2.8.11.2-win32-x86.zip"
> unzip cmake-2.8.11.2-win32-x86.zip
>
> Alan
> __________________________
> Alan W. Irwin
>
> Astronomical research affiliation with Department of Physics and Astronomy,
> University of Victoria (astrowww.phys.uvic.ca).
>
> Programming affiliations with the FreeEOS equation-of-state
> implementation for stellar interiors (freeeos.sf.net); the Time
> Ephemerides project (timeephem.sf.net); PLplot scientific plotting
> software package (plplot.sf.net); the libLASi project
> (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
> and the Linux Brochure Project (lbproject.sf.net).
> __________________________
>
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__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
__________________________