Re: MS-Windows build using Posix configury

[Stephen Leake <stephen_leake@member.fsf.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Stephen Leake <stephen_leake@member.fsf.org>
>> Date: Sun, 19 May 2013 01:48:49 -0500
>> 
>> >>     It is always preferable to use --prefix to configure Emacs for
>> >>     some specific location of its installed tree; the default
>> >>     /usr/local is not suitable for Windows.
>> 
>> It would be best to say _why_ you think "/usr/local is not suitable for
>> Windows". Certainly Microsoft doesn't care about "/usr/local".
>
> It's funny how the most obvious things draw most of the questions.
> Here are 2 obvious reasons which I had in mind when I wrote that:
>
>  . /usr/local does not specify a drive letter, so its location is
>    ambiguous, as it depends on the current drive

That's a good point.

>  . Windows systems don't usually have /usr/local on _any_ drive, even
>    if they have many MinGW packages installed, while one of the main
>    goals of this build was to allow installing Emacs as part of a
>    larger tree of ported software, not as a stand-alone package

I assume 'make install' will create the directory, so that's not a
problem.

> There's also a subtler problem, already mentioned in this thread,
> which might be known to fewer people:
>
>> Neither does MSYS or MinGW (if installed in the default places).
>
> You are wrong here: MSYS does care.  It maps /usr/local to a
> subdirectory of its installation root.  So if MSYS was installed in
> C:\MSYS, /usr/local will be actually C:\MSYS\local (note that the
> 'usr' part disappeared, because MSYS maps both / and /usr to the same
> place).  Imagine the surprise of a newbie who says "make install" and
> then looks in vain for any "usr/local" directory anywhere, and doesn't
> find it!

Right. I forgot that 'make install' is run from an MSYS shell, not a DOS
or Cygwin bash shell.

> Since INSTALL.MSYS cannot be a treatise on MSYS or anything near it, I
> thought that it will be sufficient to say "not recommended", and rely
> on people to know about the 2 obvious reasons above, and just go with
> the recommendation.  How naive of me...

That would be true for naive users. 

For Emacs users used to customizing things on Linux, the additional
information is helpful. A pointer to a thorough discussion of MSYS
issues would be very nice, but I don't think such a thing exists :(.

A pointer to an Emacs W32 FAQ would be another choice.

> Also:
>
>> Cygwin might, if installed at c:/ (as I do). In that case, it would
>> appear your MSYS/MinGW Emacs build is a Cygwin build, which would be
>> confusing.
>
> Here, you actually answered your own question: there are Emacs users
> on Windows who do actually have Cygwin installed.

Actually not, since MSYS treats "/usr/local" as Cygwin
"/cygdrive/c/MSYS/local".

-- 
-- Stephe