The Package 'flet' (build: ()) is not available from any of the selected providers

[anchpop]

Hey! Thanks for the amazing library. I'm running into a problem when depending on flet.

       > The Package 'flet' (build: ()) is not available from any of the selected providers ['nixpkgs', 'sdist', 'wheel']
       >  for the selected python version
       > The required package might just not (yet) be part of the dependency DB currently used.
       > The DB can be updated by specifying 'pypiDataRev' when importing mach-nix.
       > For examples see: https://github.com/DavHau/mach-nix/blob/master/examples.md
       > If it still doesn't work, there might have been an error while building the DB.
       > Please open an issue at: https://github.com/DavHau/mach-nix/issues/new

requirements.txt:

pygame~=2.1
pynput~=1.7.6
watchdog~=2.1
future~=0.18.2
flet

env/ was generated with mach-nix env ./env -r requirements.txt, but I modified inputs.nix's python, pypiDataRev, and pypiDataSha256:

with builtins;
let lock = fromTOML (readFile ./lock.toml);
in rec {
  pkgs = import (builtins.fetchTarball {
    name = "nixpkgs";
    url = "https://github.com/nixos/nixpkgs/tarball/${lock.nixpkgs.rev}";
    sha256 = "${lock.nixpkgs.sha256}";
  }) {
    config = { };
    overlays = [ ];
  };
  mach-nix = import (builtins.fetchTarball {
    url = "https://github.com/DavHau/mach-nix/tarball/${lock.mach-nix.rev}";
    sha256 = lock.mach-nix.sha256;
  }) {
    python = "python311";
    pypiDataRev = "e9571cac25d2f509e44fec9dc94a3703a40126ff";
    pypiDataSha256 = "sha256:1rbb0yx5kjn0j6lk0ml163227swji8abvq0krynqyi759ixirxd5";
    inherit pkgs;
  };
}

mach-nix installed with nix-env -if https://github.com/DavHau/mach-nix/tarball/3.5.0 -A mach-nix.

Any idea what might be causing this?