Fail to build python script from nixpkgs as appimage

[selfhoster1312]

Hello, i used nix-appimage in the past and it was a joy! However i'm now failing when trying to build a weasyprint appimage. Here's the output:

$ nix bundle --bundler github:ralismark/nix-appimage nixpkgs#python311Packages.weasyprint
error:
       … while calling the 'derivationStrict' builtin

         at //builtin/derivation.nix:9:12: (source not available)

       … while evaluating derivation 'python3.11-weasyprint-59.0-x86_64.AppImage'
         whose name attribute is located at /nix/store/d5c6h5p16jg2rna7db5y4s3y19dmwvx6-source/pkgs/stdenv/generic/make-derivation.nix:278:7

       … while evaluating attribute 'buildCommand' of derivation 'python3.11-weasyprint-59.0-x86_64.AppImage'

         at /nix/store/d5c6h5p16jg2rna7db5y4s3y19dmwvx6-source/pkgs/build-support/trivial-builders.nix:73:14:

           72|     stdenv.mkDerivation ({
           73|       inherit buildCommand name;
             |              ^
           74|       passAsFile = [ "buildCommand" ]

       error: main program /nix/store/1z9djg8r09lfpri1mlzf2cbqi8hsmr19-python3.11-weasyprint-59.0/bin/python3.11-weasyprint does not exist

I guess it's because the executable is called weasyprint and not python3.11-weasyprint. I think it's related to #3. Alternatively, is there something to fix on the package itself to make that possible?

EDIT: Manually creating a symlink in the nix store (yes that's evil!) made it work. I'll use that workaround for the moment but it's not elegant ;)

[ralismark]

The least hacky fix right now is to set the package's meta.mainProgram to the right path e.g. "/bin/weasyprint". But also yeah, doing this is annoying and not really possible for some packages, which is why I've been meaning to do #3.

[ralismark]

I added ./bundle so this should be possible now:

$ ./bundle python311Packages.weasyprint weasyprint
$ ./weasyprint-x86_64.AppImage --version
WeasyPrint version 58.1

Let me know if this is still an issue.