[Python-apps-team] Bug#897909: mypaint: Unable to install MyPaint when Gimp 2.10 is installed

[Jacob Nevins]

I wrote:
> There's a patch (to mypaint rather than libmypaint) to resolve the
> conflict without a new version of mypaint, by renaming mypaint's locale
> to 'mypaint12', in the upstream tracker at
> <https://github.com/mypaint/mypaint/issues/918#issuecomment-433645267>.
> 
> This is the approach previously suggested by Chris Waters in
> <https://bugs.debian.org/894757#25>.
> 
> I haven't tested it myself, but it looks plausible.

I have now tested this patch on my Buster system. It appears to work.

What needs to happen next, to fix this in Buster? I probably won't be
able to upload to the Debian archive myself.

Now that we have a simple and apparently workable solution, should the
buster-ignore tag be removed from #906144, to make this an RC bug once
again?

=-=-=-=-=-
What I did, in detail:

Starting with buster's mypaint_1.2.0-4.1, I added the above patch
verbatim to the debian/patches stack, updated debian/changelog, and
built new binary packages. I didn't have to make any changes.

Starting with buster's libmypaint_1.3.0-2.1, I simply edited
debian/control to remove the Conflicts:

--- debian/control      2019-02-09 11:22:40.000000000 +0000
+++ ../../libmypaint-1.3.0/debian/control       2019-06-02 12:50:07.776325535 +0100
@@ -59,7 +59,7 @@
 Architecture: all
 Multi-Arch: foreign
 Depends: ${misc:Depends},
-Conflicts: mypaint-data
+Conflicts: mypaint-data (<< 1.2.0-4.1jtn1)
 Description: brush library for mypaint - common files
  MyPaint is a pressure- and tilt-sensitive painting program which works well
  with Wacom graphics tablets and other similar devices. It comes with a large

(that version being the name I gave to my local mypaint build)
and updated debian/changelog and built new local binary packages.

Before installing, I verified that my mypaint-data and libmypaint-common
binary packages no longer had any files in common (where the buster
packages have a lot of .mo files in common).

Testing:

I started with GIMP (and hence buster's libmypaint_1.3.0-2.1) installed.
Before changing anything, I had a quick play with GIMP's "MyPaint
brushes" feature, which I'm not familiar with. (It doesn't seem to have
any brushes by default, but I was able to scribble.)

I installed my new local libmypaint and libmypaint-common packages (the
ones GIMP uses), and verified there was no change in GIMP's behaviour as
far as I could tell.

I installed my new local mypaint and mypaint-data packages. They
installed fine. MyPaint runs and appears functional.
I have an en_GB locale, and MyPaint talks about "colour" rather than
"color", so I infer that the .mo files are installed correctly.