bug#42844: 27.1; Emacs 27.1: SVG file not rendered as image

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 19 Aug 2020 19:33:26 +0100
> From: phillip.lord@russet.org.uk
> Cc: Eli Zaretskii <eliz@gnu.org>, 42844@debbugs.gnu.org, gbiotti@gmail.com
> 
> Pretty sure all of this stems from 61c2183a440. I dropped using pactree 
> and used pacman directly to determine dependencies. I also exclude glib2 
> as a dependency hence the problem. If I include this, we go back to 
> getting python and half the of msys2 included in the download bundle.

Too bad MSYS2 use such a "maximalistic" approach to dependencies.

> I guess for Emacs-27 I should just include glib2 and be exclude so of 
> its dependencies (gettext and python probably).

Something like that, yes.

> The question is whether to do this for Emacs-27.1 or 27.2.

I'd prefer 27.1, of course, if you can afford working on this soon
enough.  Because 27.2 is at least a couple of months away.

> For Emacs-28, I think I need a better dependency mechanism than looking 
> at msys2, perhaps based around the shell script that was sent earlier, 
> or an automated (or horror manual) use of dependency walker.

If you have Binutils installed (which you must, since you build
Emacs), you can find dependencies by recursive application of
objdump.  E.g., the following command will show all the DLLs of all
the binaries in a directory:

    objdump -p *.exe *.dll | fgrep "DLL Name:" | gawk " {print $3, $4, $5}" | sort -u

You need to rerun this each time you add one or more DLLs to the soup,
until all the DLLs you see in the list are present in the directory.