Re: [feature/internal-msys] thoughts of a more function windows package

[Eli Zaretskii <eliz@gnu.org>]

> From: Phillip Lord <phillip.lord@russet.org.uk>
> Cc: emacs-devel@gnu.org
> Date: Thu, 21 Jan 2021 16:44:02 +0000
> 
> > Could you please elaborate on how will this work for users?  E.g., how
> > about describing the steps a user who installs Emacs should do to
> > install these additions?  I don't think I have a clear picture of what
> > you intend to do, and the files you committed are just the starting
> > point, so they don't answer this question.
> 
> Considering just the .exe installer, at the end of the installation
> process, we would run Emacs with menu bar, scroll bar and everything
> switch off and run the command "w32-msys-internal-install-dialog".

"We" being the installation process?  IOW, this will start
automatically at the end of the normal installation?

> Emacs would say "do you want do install a handy collection of
> tools". User says "y", then Emacs downloads the latest msys2-date.xz,
> then unpacks it with xz. Emacs will run msys2.exe to initialize
> (hopefully without poping up windows if this will work). Then Emacs will
> run pacman to update and install. The user will see Emacs saying
> 
> Would you like to install msys, and a handy set of tools (Y/n)
> Installing msys...done
> Updating msys...done
> Installing git...done

First, why Git?  This is a "normal" user, not an Emacs developer,
right?  Git is a huge package (and comes with Vim on top of that), so
maybe reconsider that part.

Next, by "msys" you mean all those non-native programs that depend on
msys-1.0.dll?  That's again meant for MinGW developers, not "normal"
users.

And finally, which packages will pacman install? are you going to
provide some list of packages, and if so, what will be there?

(Btw, pacman can ask questions and prompt the user for confirmation,
but the way you invoke it in w32-msys-run doesn't seem to be prepared
for such interaction?)

One other aspect that bothers me is that if the user already has some
parts of MSYS/MinGW64 installed, they will now have two places with
DLLs, which is a step towards "DLL hell".

> We might create "internal-msys" package on ELPA which
> contains a standard set of packages and Emacs fixes to make it work, so
> it would be freely updatable. At which point the w32-msys-install
> command would install the ELPA package before doing anything else.

Is it really possible for us to distribute MSYS, given its license?

> > Btw, I don't think I understand why you insist on using 'concat' to
> > generate files names from 2 components: that's what expand-file-name
> > is for, and it does that better.
> 
> Because in my own code, I tend to use f.el and I have got used to having
> a clean, consistent and comprehensive API, so I tend to forget the
> underlying Emacs primitives.

Then I think f.el has a big problem.

> > One other not about the code you committed is that modifying PATH from
> > within Emacs is not generally a good idea, it has some subtleties.
> 
> Any alternative that achieves the same thing?

I think the only good idea here is to tell the user to amend PATH by
adding such-and-such directories to it.  I don't like installers that
futz with my PATH, and would hate it if Emacs did that to others.
It's very easy to get that wrong, especially on Windows.