libvterm.so.0: cannot open shared object file: No such file or directory on ubuntu-20.04

[Sbozzolo]

I am trying to set up CI for vterm with GitHub Actions, but I cannot get it to work with Ubuntu 20.04. No matter what I do, I always have the error libvterm.so.0: cannot open shared object file: No such file or directory". It works with Ubuntu 16.04.

See, https://github.com/Sbozzolo/emacs-libvterm/runs/912526858?check_suite_focus=true, tab "require vterm".

I don't know much about all the moving parts, so maybe I am missing something obvious.

Could it be a bug somewhere, or am I missing something obvious?

A user reported success, with the following comment:

With my limited nix knowledge I made ci.nix to build vterm-module.so which setup-emacs's emacs can load.
https://github.com/tsuu32/emacs-libvterm/runs/1222306107

Thanks for the help
Originally posted by @tsuu32 in akermu/emacs-libvterm#410 (comment)

[purcell]

Thanks for getting in touch - what's your goal in asking this question? From what I can see above, somebody has demonstrated how to get this working. If you're asking why you can't get it to work under Ubuntu, probably the important thing to know is that Nix binaries don't see the system-wide installed libraries, so even if you could get an Emacs to try to load the vterm emacs module, it would not be able to resolve libvterm installed via apt.

[Sbozzolo]

My initial impression was that the proposed fix was more of a workaround than a real solution. However, given your comment, I now see why attempts failed and how that could be the way to go.

I assumed there was a bug somewhere because everything works in Ubuntu 16.04. The reason it works is because libvterm is too old on Ubuntu 16.04, so I don't install it with apt.

Thanks!

[akirak]

@Sbozzolo A proper way to configure Emacs in Nix is to use emacsWithPackages: https://nixos.org/manual/nixos/stable/index.html#module-services-emacs

I was working on a project to support this without the need to write Nix: https://github.com/akirak/elinter. I haven't been working on it for a month or so, because it's become boring to further work on it. Maybe I'll rework on it.

[purcell]

Yeah, nixpkgs (the Nix package DB) actually already has libvterm 0.1.3 (as "libvterm-neovim"), so if that's sufficient, you can probably dispense with the ci.nix and simply compile the vterm module in a nix-shell with the appropriate tool packages available, e.g.

nix-shell -p libvterm-neovim -p cmake -p libtool --run "mkdir build && cd build && cmake .. && make && ldd ../vterm-module.so"

And if you start emacs inside such a shell, it might have what it needs to compile the module itself.