Change:
zlib clang git # for git-based packages in unity package manager <ins> # Unity Editor 2019 specific dependencies xorg.libXi xorg.libXrender gnome2.GConf libcap </ins> ] ++ extraLibs pkgs; };

Discussion:
Unity Hub can't create or open a project using Unity Editor 2019.4.39f1. Steps to reproduce the behavior: on nixos 23.05 unityhub (3.4.2) unityhub open, go to the and press the "Unity Hub" button for the 2019.4.39f1 version. the editor without any additional component. to create a new project, or open a project that is already for 2019.4.39f1. It was expected that the editor would open the project. Screenshot of the editor failing silently to create a new project. ! Screenshot of trying to re-open the new "ghost project". ! If you try to create a new project, it will hang and then silently fail, creating a "ghost project", as seen on the screenshots. And if you try to open a previously created project, it will hang and then silently fail. <!-- Please @ people who are in the list of the offending package or module. If in doubt, check for whoever last touched something. -- Please run and paste the result.
Could you upload the log files , as well as try running the app from the command line and seeing if there's any relevant information in the command line output?
Here is the log file: And there is no relevant information that appears on the command line output when trying to run the editor, only these two lines when starting the hub:
Sorry, that paste didn't have my attempts at creating/opening a newly created project, here is the log file for that
This may be a unity editor crash, can you check if has any info after trying to open the diffferent projects? If it's an editor crash, it may be due to this being a version of unity that uses OpenSSL 1.1, and doesn't support OpenSSL 3. If that's the case, you might want to try to add the deprecated version of openssl to unity yourself:
No file was generated for 2019.4.39f1. I also tried with the overridden package but same result. Edit: I only have logs from trying to open projects with 2021.3.26f1, if those are helpful.
Hm this is very strange, just to clarify, it works with newer versions of Unity?

It opens newer versions of Unity, but they have the same issue as Overriding extraPkgs to use openssl11 sadly didn't help, maybe it is because there is already openssl in there, and it is trying to first load it instead of openssl11?
I did get the OpenSSL issue on an older version of 2021, but it disappeared after upgrading to 2022. A newer version of 2021 might also fix the issue. Kinda a long shot but maybe overriding extraLibs instead of extraPkgs would do something different?
Yeah, sadly that didn't change anything.
Hm just tested myself and adding to did seem to make the libssl error go away in one of my 2021.3.16f1 projects. Is there some reason that this wouldn't be consistent across systems? I'm not sure if we should even support Unity 2019, since it is end of life on Unity's side, I believe.
Sadly I need it for modding, because assetbundles are very version dependent, so I at least the same major version. Also did it work with just changing the hub, or did you need to reinstall the editor?
These were the steps I did: the hub and the project, note the error. the hub. my system config with the change and rebuild the hub and the project, no error. Didn't need to reinstall the editor, this was on editor
Oh strange, I redid the steps and it is working with , but this time I opened the hub from the terminal, maybe it is related to me installing it on the user. But sadly is still a no go, well at least that solves part of the problem, thanks.
I'll post this as a solution to , but we'll have to probably do some more research for 2019.
For debugging purposes, can you get the log file from a session where all you do is launch the hub, and try to open a 2019 project?
Sadly pastebin didnt allow the file because of its size, but here it is From looking at it, the error is talking about missing path, but the project is 100% there, as I got it from cloning a repository.
Relevant errors for users following: My one guess would be to remove the space in the project name? Otherwise I'm unsure what could be causing this.

Perhaps older Unity editor doesn't handle spaces in project names correctly. I saw this thread on reddit but might not be relevant.
Renamed the project to , strangely that project is for unity 2021, not unity 2019, but either way it still didn't work, here is the new log file The project I tried to open with unity 2019 is called . Found these strange messages on line 2301, it is erroring when creating a new project, but the editor was spawned to open an existing project.
I'm having the same issue on . I installed to test and it works correctly on that version. If only the logs were more verbose...
I've been putting off actually testing locally, but since multiple people are having this problem, I'll see if I have any luck reproducing this on 2019 later today.
I tried manually initializing a project by extracting the template from the given path under the installed Unity version. Seems like it still exits Unity on launch with the same exit code.
Man this was such an easy problem to solve, the 2019 version of the editor simply depended on some extra libraries that the newer version no longer depend on. I'll list them here so you can add them temporarily, and I'll also update the package to include them. For future reader's reference, because the unityhub log didn't include which libraries we were missing, I instead manually ran the editor from the FHS env directly. To find the path to the FHS env, I usually the binary, which is a simple wrapper that runs the real binary with the FHS env, so you can just copy the path to the FHS env from there. Perhaps I'll add a simple run script that does something similar to , which can help with debugging these issues, and could also be useful for launching dev tools and such. I'll keep this issue open until I get extra confirmation this works, and the extra libraries are to the main package.
It indeed works with the missing dependencies. Thanks a lot for your help.