I also added factorio-demo-experimental.

@priegger Builds fine, but when I run the experimental demo and start a tutorial, I get this error:

  34.203 Error AppManager.cpp:640: Error while running reload_script: filesystem error: copy_file "/nix/store/a78qwkia1dr8h2akq7lsijnw9dy665h1-factorio-demo-0.18.30/share/factorio/data/base/campaigns/tutorial/lualib/new-hope-util.lua" to "/home/justin/.factorio/temp/currently-playing/new-hope-util.lua" failed: Permission denied [/nix/store/a78qwkia1dr8h2akq7lsijnw9dy665h1-factorio-demo-0.18.30/share/factorio/data/base/campaigns/tutorial/lualib/new-hope-util.lua] [/home/justin/.factorio/temp/currently-playing/new-hope-util.lua]

I guess this is due to state in my home directory, but could you verify that you can start a tutorial in the demo? If yes I'll approve the PR, wouldn't need to to test it myself in this case.

@erictapen: Thanks a lot, I missed this problem.

I cannot start the tutorial in the demo. I think the problem is, that files from factorio get copied into the user home and then cannot be changed anymore. The current non-experimental (0.17.79) factorio-demo has the same problem.

I now remember, I also saw this before in the non-demo factorio version. I hacked around it with a "while true; chmod ug+w .factorio; done" or something like that.

Might be related to #39807.

I guess I just drop that commit and don't add a (broken) factorio-demo-experimental for now.