Xournal seems broken on 20.09

Hi all,
as per subject after having upgraded from 20.03 to 20.09
I discover that xournal (a GUI mostly useful to add text or
images to pdfs) go sigsegv,

stderror here: https://paste2.org/dBeagW1z

full strace: http://kfx.fr/nixos/xournal-nixos20.09-strace

Xournalpp (a fork with minor changes) does work though.

After the upgrade I’ve experienced few fonts issue, especially
Emacs/EXWM freeze on certain unicode char displayed with
unclear (to me) errors in the C core, unlocked with kill -SIGUSR2
works, blasting font cache (fc-cache -fr) seems to help, at least
Emacs now works properly, but not Xournal…

Maybe relevant part of my NixOS config

  fonts = {
    enableFontDir = true;
    enableGhostscriptFonts = true;
    fonts = with pkgs; [
      inconsolata
      fira-mono
      fira-code
      fira-code-symbols
      fira
      font-awesome-ttf
      cantarell-fonts
      ubuntu_font_family
      cm_unicode
      bakoma_ttf
      gyre-fonts
      league-of-moveable-type
      noto-fonts
      noto-fonts-emoji
      stix-otf
      powerline-fonts
      emacs-all-the-icons-fonts
      freefont_ttf
      google-fonts
    ];
  }; # fonts

Does anyone have an idea?

Thanks!

– Ingmar