I just tried it on NixOS 24.05. It starts, but nothing happens when I click "Open a project" or Ctrl+O. It's as if it lacks the ability to show a file selection dialog.
It's unfortunate that the documentation for XDG desktop portals (and generally, setting up a complete desktop setup when using compositors like labwc or Sway) is relatively poorly documented. I have my feelings about the pervasiveness of DBus services everywhere but overall I like desktop portals.
But now I get issues that are likely due to problems with downloading language server binaries and running them, as the parent comment indicated. When I open a Rust project it says "Language server rust-analyzer-2024-07-08 (id 1) status update: Failed to load workspaces."
Also, it dumps core every time I quit. :)