bug#19989: 25.0.50; Build instructions on Windows

[Eli Zaretskii]

> Date: Thu, 5 Mar 2015 13:18:21 -0800
> From: Ilya Zakharevich <ilya@math.berkeley.edu>
> Cc: 19989@debbugs.gnu.org
> 
> On Wed, Mar 04, 2015 at 05:42:59AM +0200, Eli Zaretskii wrote:
> > > > > >   • mingw shell sets path to (essentially) FOO/msys/1.0/mingw/bin 
> > > > > > (here FOO
> > > > > >         is the install path), but there is no directory
> > > > > >           FOO/msys/1.0/mingw
> > > > > >         what is is
> > > > > >           FOO/bin
> > > > > >     So I needed to make a symbolic link (Windows style required) by
> > > > > >     running
> > > > > >         mklink /j mingw FOO
> > > > > >     in FOO/msys/1.0
> > > 
> > > > > FWIW, the 2nd issue sounds to me like an installation mistake of some
> > > > > kind (did you install MinGW inside the MSYS tree, by chance?).
> > > 
> > > How would I know?
> > 
> > You could look at the directory hierarchy that got created.
> 
> *This* I did — and I reported the result in my initial message (quoted
> below).  This does not answer your question.

It doesn't answer the question, indeed, because you didn't say where
MinGW programs are, only what PATH you see in the MSYS shell window.
And the PATH you reported was not exactly what you saw, AFAIU, at
least that's what follows from the "(essentially)
FOO/msys/1.0/mingw/bin" part.

> > > I just ran mingw-get (as described), and set
> > > install directory ( = FOO) once.
> > 
> > Did you select the same install directory for MinGW and for MSYS?
> 
> AFAIR, there was no “install directory ‘for”’.  Only “install directory”.

I'm asking if they share the same directory tree.  Can you show the
entire tree, e.g. by running 'find -type d'?

> > > The result:
> > >   FOO/bin         - contains gcc executables etc
> > >   FOO/msys/1.0/           - contains msys
> > >   FOO/msys/1.0/bin        - contains msys executables
> 
> > > > >  But
> > > > > I'm not an expert; all I know is that on my system, the MSYS Bash
> > > > > window has PATH set to whatever my system-wide PATH is, with these
> > > > > directories prepended:
> > > > > 
> > > > >   .:/usr/local/bin:/mingw/bin:/bin:
> > > > > 
> > > > > IOW, no msys/1.0/mingw/ anywhere in sight.
> > > 
> > > ???  Of course it IS in sight:
> > > 
> > >   /bin           IS native   FOO/msys/1.0/bin
> > >   /mingw/bin   IS native   FOO/msys/1.0/mingw/bin
> > 
> > But then there's no problem, because missing directories on PATH do no
> > harm.
> 
> Of course they do.  configure did not work (since the gcc found on
> path was not MINGW one).

So that's the problem: you installed the MSYS GCC (and probably the
whole MSYS development environment), something one shouldn't do for
building MinGW programs.  The MSYS GCC and development environment is
for developing MSYS programs, like the MSYS Bash etc. -- you don't
want and don't need that.

> > The binaries are in /bin, and it is on PATH, so there should be
> > no problem; there isn't one in my installation.
> 
> Are you joking?!  What do you think is a reason for filing bug
> reports?  I followed instructions, AND GOT PROBLEMS!

Well, now I at least understand the reason for your problems: an extra
development environment that gets in your way.  I didn't understand
that before, sorry for being too stupid.

> > /etc/profile is a standard place in many Posix shells.
> 
> How would it help?  How would the user find it on their disk?
> 
> > > As you see, even
> > > *you* got lost what denotes which native directory.  If what the users
> > > know is what is in nt/INSTALL, they have no way to deduce this info.   
> > 
> > I wasn't talking about some abstract user, I was trying to help you to
> > get your installation in good shape.
> 
> Thanks!  But did I ask for that?  This is a bug report, not a cry for
> help.

I don't think it's a bug report about Emacs.  Your development
environment was botched (and maybe still is, if you didn't uninstall
the MSYS GCC).

> > > BTW: you reminded me: there is another bug in Emacs build — this one
> > > purely in Emacs.  My default PATH accesses a complete cygwin
> > > installation
> 
> > How does Cygwin enter this equation?  Do you have both Cygwin and
> > MinGW/MSYS installed?
> 
> I have tens of environment installed.  cygwin is on PATH.

I suggest to remove it.  You might have additional runtime problems,
e.g. if there are DLLs there that Emacs looks for, whose names are
identical to their MinGW namesakes.  It's a problem waiting to happen.
You can avoid it by being extra-vigilant, and carefully set up the
order of directories, but it's easier to side-step the problem to
begin with.

> > If you mix incompatible stuff in the same shell session, you get what
> > you deserve.
> 
> Sigh…  Again — all I did was following instructions in nt/INSTALL.

If those instructions somehow cause you to download the MSYS
development environment, please tell how to amend them as to avoid
that.  These instructions exist for quite some time, and no one has
bumped into this particular problem yet.  (I myself don't use
mingw-get, so the part in the instructions for using it was provided
by someone else who did.)

> >  My advice is to have MSYS in separate tree from MinGW,
> 
> Is this advice in nt/INSTALL?

Yes:

  MSYS packages should be installed in a separate tree from MinGW.
  For example, use D:\MSYS or D:\usr\MSYS as the top-level directory
  from which you unpack all of the MSYS packages.

> And how to do it from mingw-get?

If someone knows how to do that with mingw-get, please tell.

> > and only let MSYS shell see MinGW executables _after_ its own.  MinGW,
> > OTOH, should not have the MSYS's /bin directory on its PATH.
> 
> Same questions.

Same answers:

  Do NOT add the MSYS bin directory to your Windows Path!  Only the
  MinGW bin directory should be on Path.  When you install MSYS, it
  creates a shortcut on your desktop that invokes the MSYS Bash shell
  in a Command Prompt window; that shell is already set up so that the
  MSYS bin directory is on PATH ahead of any other directory.  Thus,
  Bash will find MSYS executables first, which is exactly what you
  need.

> > As for Cygwin, it should be in yet another segregated tree,
> 
> It is.
> 
> > and never on the same PATH as either MSYS or MinGW.
> 
> It was not in *MY* $PATH.  It was in the $PATH created by /etc/profile
> which was created following instructions in nt/INSTALL.

/etc/profile just takes your PATH and prepends a few directories to
it, that's all.

> > It is next to impossible to have
> > the Posix configure scripts distinguish between foo.exe or foo.h that
> > are for Cygwin and their namesakes for MinGW.
> 
> For foo.exe — one does not care.  For foo.h — one compiles and runs a
> simple program.

See above: you forget the DLLs, for which Windows has quite a
convoluted search algorithm.

> > Like I said: you need to get your MinGW/MSYS installation in good
> > shape, and then things will work seamlessly.  This isn't an Emacs
> > issue, per se.
> 
> Again: this is an issue with nt/INSTALL.

We need to identify the issues first.

One issue is now clear: the MSYS development environment should not be
installed.  The manual instructions take care of that: they provide a
list of packages to install; for the mingw-get instructions I'd
appreciate if someone who uses it says how to avoid it.

The other part is Cygwin; if you want to keep it on PATH, and you know
what you are doing, fine.  It's not the job of nt/INSTALL to tell
users how to configure their systems to avoid future trouble.

Are there any other issues?  If so, can you suggest specific changes
to nt/INSTALL.