Change:
<ins> { stdenv , lib , fetchFromGitHub , python3 , wrapGAppsHook , gobject-introspection , gtk3 , gdk-pixbuf # Recommended Dependencies: , unrarSupport ? false , unrar , p7zip , lhasa , mupdf }: python3.pkgs.buildPythonApplication rec { pname = "mcomix3"; version = "unstable-2020-11-23"; # fetch from github because no official release on pypi/github and no build system src = fetchFromGitHub { repo   = "${pname}"; owner  = "multiSnow"; rev = "cdcb27533dc7ee2ebf7b0a8ab5ba10e61c0b8ff8"; sha256 = "0q9xgl60ryf7qmy5vgzgfry4rvw5j9rb4d1ilxmpjmvm7dd3fm2k"; }; buildInputs = [ gobject-introspection gtk3 gdk-pixbuf ]; nativeBuildInputs = [ wrapGAppsHook ]; propagatedBuildInputs = (with python3.pkgs; [ pillow pygobject3 pycairo ]); format = "other"; # Correct wrapper behavior, see https://github.com/NixOS/nixpkgs/issues/56943 # until https://github.com/NixOS/nixpkgs/pull/102613 strictDeps = false; preInstall = '' libdir=$out/lib/${python3.libPrefix}/site-packages mkdir -p $out/share/{icons/hicolor,man/man1,applications,metainfo,thumbnailers} mkdir -p $out/bin $libdir ''; installPhase = '' runHook preInstall ${python3.executable} installer.py --srcdir=mcomix --target=$libdir mv $libdir/mcomix/mcomixstarter.py $out/bin/${pname} mv $libdir/mcomix/comicthumb.py $out/bin/comicthumb mv $libdir/mcomix/mcomix/* $libdir/mcomix runHook postInstall ''; postInstall = '' rmdir $libdir/mcomix/mcomix cp man/* $out/share/man/man1/ cp -r mime/icons/* $out/share/icons/hicolor/ cp mime/*.desktop $out/share/applications/ cp mime/*.appdata.xml $out/share/metainfo/ cp mime/*.thumbnailer $out/share/thumbnailers/ for folder in $out/share/icons/hicolor/*; do mkdir $folder/{apps,mimetypes} mv $folder/*.png $folder/mimetypes cp $folder/mimetypes/application-x-cbt.png $folder/mimetypes/application-x-cbr.png cp $folder/mimetypes/application-x-cbt.png $folder/mimetypes/application-x-cbz.png done ''; # to prevent double wrapping dontWrapGApps = true; preFixup = '' makeWrapperArgs+=( "''${gappsWrapperArgs[@]}" "--prefix" "PATH" ":" "${lib.makeBinPath ([ p7zip lhasa mupdf ] ++ lib.optional (unrarSupport) unrar)}" ) ''; # real pytests seem to be broken upstream checkPhase = '' $out/bin/comicthumb --help > /dev/null $out/bin/${pname} --help > /dev/null ''; meta = with stdenv.lib; { description = "Comic book reader and image viewer; python3 fork of mcomix"; longDescription = '' User-friendly, customizable image viewer, specifically designed to handle comic books and manga supporting a variety of container formats (including CBR, CBZ, CB7, CBT, LHA and PDF) ''; homepage = "https://github.com/multiSnow/mcomix3"; changelog = "https://github.com/multiSnow/mcomix3/blob/gtk3/ChangeLog"; license = licenses.gpl2Plus; maintainers = with maintainers; [ confus ]; platforms = platforms.all; }; } </ins>

Discussion:
Describe the bug There is a fork of mcomix, mcomix3, that's is currently in use by debian because it's ported to gtk3 and python3. A big issue though is it lacks a real build system to install If anyone is up to maintaining this I could contribute cc
I haven't used mcomix for a long time. I just removed myself from all the maintainer lists to not cause further confusion on who to ping for what.
I use mcomix semi-regularly, so I'd definitely appreciate having this fork in nixpkgs. Than again, we do have yacreader, so I guess I'll just switch to that.
Wow! Good to know! I wanna test it!
please contribute back to upstream if you finish this, so that all distro packagers benefit.
Thank you for your contributions. This has been automatically marked as stale because it has had no activity for 180 days. If this is still important to you, we ask that you leave a comment below. Your comment can be as simple as "still important to me". This lets people see that at least one person still cares about this. Someone will have to do this at most twice a year if there is no other activity. Here are suggestions that might help resolve this more quickly: for maintainers and people that previously touched the related code and @ mention them in a comment. on the . on the on .
I would like to adopt mcomix and take you up on your offer to help, if it still stands. The mcomix devs seem not very happy about meson or any other build system, so I tried without. What I got so far is: but there seems to be a problem with and/or pygobject, that I don't know how to resolve: This is with a special debug version, I think the message about GTK+ 3.0 might be a red herring.
Chute! I forgot to it, that was the problem. I think, I have it working now, but need help polishing, seeing this would be my first contribution. Edit: Well, not quite, it's starting now, but in some dialogs, I get a crash with , which I remember seeing somewhere in the nix manual FAQ.
Can you post the code in a gist or in a local Github clone?

Sure:
I made some comments there.
This issue has been mentioned on NixOS Discourse. There might be relevant details there: