Bug 24018 which appears to be a showstopper for running Cygwin on Wine

[Alan W. Irwin]

On 2013-06-26 23:43+0100 Hin-Tak Leung wrote:

> --- On Tue, 25/6/13, Alan W. Irwin <irwin at beluga.phys.uvic.ca> wrote:
>
> <snipped>
>> I currently have no experience with Cygwin and my only real
>> interest
>> in Cygwin on Wine is it theoretically provides an
>> alternative build
>> platform to my present successful work with the combination
>> of MinGW,
>> MSYS, and Wine as a Windows build platform. But I haven't
>> even been
>> able to get started with Cygwin on Wine because of this
>> showstopping
>> bug. Therefore, I am mentioning the situation here in the
>> hope that
>> some wine developer on this list with some knowledge of
>> Cygwin will
>> take the responsibility of making a proper bug report to the
>> Cygwin
>> mailing list (which according to http://cygwin.com/problems.html is
>> the correct place to report Cygwin bugs) including the
>> evidence that
>> the issue is a Cygwin regression (assuming investigation of
>> older Cygwin
>> versions with Turkin's test supports that conclusion).
> <snipped>
>

> FWIW, the fact that cygwin's setup has problems working doesn't not
> stop you from *trying* cygwin - it doesn't do very much more than just
> unpacking tar.tgz files, which you can do manually. And for many
> command-line utilities, just have the exe and the dll around is
> enough.

One of the disadvantages of MinGW/MSYS as a build platform is you
pretty much have to build all your own free software libraries to keep
ABI/API consistent.  However, it is not too bad because 
I am automating that process with my "build_projects" project.

One of the theoretical advantages of Cygwin as a build platform is
access to lots of free libraries that have been built with a
consistent "Cygwin" ABI/API.  But I would prefer not to implement a
replacement for setup.exe that downloads and installs all of those
libraries keeping track of all library dependencies.  Instead, I would
prefer to see bug 24018 fixed so that setup.exe can be used for this
task. But that fix will likely require some rather deep knowledge of
both Cygwin and Wine.

> However, I found that cygwin version of a few utlities does not work
> correctly uner wine (it obvious does for some under genuine windows).
> While the mingw/gnuwin32 equivalent, do. echo and cat were two I had
> problems with, when I accidentally let some 3rd party's installer put
> cygwin's cat/echo in front of gnuwin32's cat/echo in my $PATH under
> cmd.

It's entirely possible that some Cygwin apps don't work correctly
under Wine, but that probably depends on both Cygwin and Wine
versions. Also, when confirming these issues, it would probably be
best to use setup.exe for installation since I doubt any Cygwin
developer would trust a Cygwin installation created by anything other
than setup.exe. So the current broken setup.exe on Wine is a pretty
big barrier to discovering, confirming, and fixing other Cygwin on
Wine issues.

> Also, I believe MSYS and Mingw do not depends on cygwin. cygwin and
> msys/mingw are rather different. For building windows applications,
> you really want to stick with mingw if you can.

I agree there are big differences between Cygwin and MinGW/MSYS and
the former has some extra baggage as a platform that some Windows
developers do not like.  But I do not mind extra Cygwin baggage at all
assuming Cygwin provides a set of free libraries that has a coherent
API/ABI.

> And, I found cross-compiling works well enough that I don't bother
> with having a mingw-based dev system under wine. And if I need MS VC
> specifically, that works well under wine so; so there has not been any
> need for running mingw or cgywin under wine for a while. I can tell
> you from first hand experience that mingw gcc/g++ works well under
> wine, but many times slower compared to cross-compiling. I think the
> speed problem comes from fork/exec being slow in wine.

For me an integral part of package building is package testing.
Cross-compilation only does the building part while Wine is quite good
for providing both a build and test platform.  I do agree with you it
is slow compared to the Linux equivalent of the same build and test
due to application startup latency issues.  My experience is the
overall slowdowns are from a factor of two to five depending on how
much the build and test timing is dominated by small tasks (i.e.,
whether the build consist of many compilations of small files or a few
compilations of large files and whether the individual tests are short
or long.) Apparently Cygwin on the Microsoft version of Windows also
has similar issues with fork inefficiency. See the discussion in
http://cygwin.com/cygwin-ug-net/highlights.html.  So I expect these
startup latency issues inevitably occur for any shell environment
(such as MSYS's bash.exe) that attempts to fork tasks on Windows.

That said, I am happy to accept such build and test slowdowns for
MinGW/MSYS or Cygwin on Wine in order to have access to free (in both
senses), realistic, and extremely convenient (no dual-booting
necessary) Windows build and test platforms.  If I ever get
inconvenienced by the factors of two to five slowdowns I have seen for
typical builds and tests I could always go out and buy a faster
computer!  :-)

Therefore, for free software developers I view MinGW/MSYS on Wine as a
pretty ideal build
and test platform.  I also plan to start trying Cygwin on Wine as a
build and test platform as soon as the Cygwin and Wine developers get
together and figure out the best way to fix bug 24018.

Note in retrospect I realized that this period leading up to the
release of Wine-1.6.0 has been a lousy time to ask wine developers
with Cygwin expertise to take on the additional distraction of getting
the debugging process for bug 24018 started with the Cygwin
developers. Therefore, if I don't get any further response now, I will
ping about this substantially (a few months) later when times
presumably won't be so hectic for Wine developers.  In any case I am
confident this important bug will eventually be solved because there
is obviously a lot of interest (just from the "me too's" in the bug
report) in running Cygwin on top of Wine.

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).
__________________________

Linux-powered Science
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