Flatpak-building a legacy GTK2 app that uses WebKit

[Dominic Delabruere]

Hello all,

Last night I was acquainting myself with flatpak-builder, and trying
to use it to build a sandboxed version of gnome-inform7 [1]. Inform 7
has not-yet-open-sourced core component and a historically slow
release cycle; the most recent release was in 2015 [2] and its
packages for popular Linux distributions are becoming antiquated as
outdated dependencies disappear from official repos. I'm not yet a
contributor to it, just a past user who wanted to try it again. So
last night I was trying to see if I could get the UI working on Fedora
29 by building it for Flatpak (instead of using a VM, or reverting
important shared libraries to a deprecated version). But I'm finding
it a little difficult to satisfy one particular dependency: a
GTK2-compatible version of WebKit. gnome-inform7 uses WebKit to
display local and dynamically generated HTML, and this is a central
part of the UI. The oldest version of org.gnome.Platform and
org.gnome.Sdk I could find was 3.24, and neither of these ships with
such a version of WebKit. I've found that compiling it is very time
consuming and brings in its own dependencies. (I've had trouble
bundling a version of geoclue that the autotools configuration for
WebKit will accept; I can get flatpak-builder to build a recent
version of geoclue with meson, but then, in the next module of my
manifest, the configuration script for WebKit reports that geoclue was
not detected. I tried an older version of geoclue before giving up for
the night, but building this version with autotools failed because of
yet another dependency.) I found some discussion on an MR for the
Flathub configuration for the GIMP [3], where it was ultimately
decided to go ahead with building WebKit as a module in the manifest,
despite all the time it added to the build. However, participants in
the discussion mention the possibility of keeping the GIMP on an older
version (of the Flatpak GNOME runtime, I'm assuming?) to avoid
problems with WebKit. Is there some Flatpak SDK/Runtime I haven't
found yet, that ships with a GTK2-compatible version of WebKit?

Thanks,
Dominic Delabruere

[1] https://github.com/ptomato/gnome-inform7
[2] http://inform7.com/download/release/6M62/
[3] https://github.com/flathub/org.gimp.GIMP/pull/37