bug#51968: Missing dependency for Xournal++

[Daniel Meißner]

Hi Alexander, hi Ludo’,

Ludovic Courtès writes:
> Hi Daniel,
>
> Daniel Meißner <daniel.meissner-i4k@ruhr-uni-bochum.de> skribis:
>
>> there is a problem with the package xournalpp on Guix master.  To
>> reproduce run:
>>
>> $ guix shell --pure xournalpp -- xournalpp

[...]

> How should this be addressed?  Adding ‘gnome-icon-theme’ as a
> propagated input would be quite unusual, but maybe it’s become
> necessary?

I have done some more analysis.  First of all, I was wrong in pointing
out it has to be ‘adwaita-icon-theme’ for it to work, ‘gnome-icon-theme’
does also work.  Of course, you then get a different ‘image-missing’
icon.  However, let me elaborate a bit:

The following command tries to invoke xournalpp in a pure and
environment.  It crashes because it cannot find ‘image-missing.png’.  It
tries to load this icon in the first place because it cannot load its
own toolbar icons.

#+begin_src bash
  guix shell --pure xournalpp -- xournalpp
#+end_src

However, when run from within Gnome it works without problems and the
toolbar icons show up.  Running the following prevents the crash but
most of the toolbar icons now show the ‘image-missing’ icon:

#+begin_src bash
  guix shell --pure xournalpp gnome-icon-theme
  export XDG_DATA_DIRS=$GUIX_ENVIRONMENT/share
  xournalpp
#+end_src

Depending on whether one uses ‘gnome-icon-theme’ or ‘adwaita-icon-theme’
different icons for ‘image-missing’ are used.

It seems to me that evince also does not find all of its icons.
However, it does not crash because it has ‘adwaita-icon-theme’ as one of
its inputs (although it is just an input, not a propagated input).  The
missing icon is the ‘view-sidebar-symbolic-ltr’ and is complained about
after opening some PDF.

#+begin_src bash
  guix shell --pure evince -- evince
#+end_src

Also in this case when run from Gnome the sidebar icon is correctly
displayed.

So in order to address the crash it seems natural to add either
‘gnome-icon-theme’ or ’adwaita-icon-theme’ to the list of inputs.  For
example, the following package definition yields a “working” Xournalpp
in the sense that it does not crash.

#+begin_src scheme
(use-modules (guix packages)
             (gnu packages pdf)
             (gnu packages gnome))

(package/inherit xournalpp
  (inputs (modify-inputs (package-inputs xournalpp)
            (append adwaita-icon-theme))))
#+end_src

Put the above in a file named ‘xournalpp-fix.scm’ and then run:

#+begin_src bash
guix shell --pure -f xournalpp-fix.scm -- xournalpp
#+end_src

Xournalpp does not crash, however, the correct toolbar icons are still
missing and this seems to be the actual problem.  Any ideas where to
look for the problem?  I have not tried to run Xournalpp in an XFCE
environment to see if the toolbar icons are missing there, too.  But
maybe Alexander has, since he discovered the problem in the first place.
As I am using Gnome, I have never run into this issue before despite
having been using Xournalpp under Guix for a while now.

Since evince also shows this behaviour in an isolated environment:
Might there be a general underlying problem?

Best
Daniel