xdg-open doesn’t know to unset any env vars for library paths, XDG_*_DIRs and so on that were set for the program calling it, and then the child process is called with a pile of additional unexpected libraries or config directories that might make it fail to start. An example of this in the wild is Discord can't open links in Firefox · Issue #78961 · NixOS/nixpkgs · GitHub
I tried to work around this by making a wrapper for xdg-open
[xdg-open-wrapper] which starts from a fresh environment but this only works for apps which don’t use buildFHSUserEnv. If you run this inside one of those, /etc/profile will look like [Example /etc/profile when in a FHS sandbox].
So you are worse off and many things won’t be set at all, and of course you’re in the sandbox now so if you start a browser it’s in the FHS sandbox of an unrelated program which we don’t want to happen.
My next idea was to try having a socket in XDG_RUNTIME_DIR which is used to signal an xdg-open request and a program running outside the sandbox waiting for them which can start xdg-open there, but I don’t know how to go about doing this correctly.
What’s a generic way to have a service start that needs to start after the desktop environment with DISPLAY and XAUTHORITY, or wayland equivalents available?
Or is there some other way to get xdg-open running in a clean env outside any FHS sandbox and without extra env vars wrappers set piling up and potentially breaking things?
I think I’ve spent a good few hours tinkering with this, all I wanted was to get the links in games I launch through lutris working. >.>
This reminds me of the “portals” that flatpaks use, which is a very similar feature all things considered. Maybe try and see if you can integrate with xdg-desktop-portal somehow? It isn’t flatpak specific as I understand it.