Currently it's not possible to determine the reason why a package is
unavailable without evaluating nixpkgs multiple times with different
settings. eg.
nix-repl> :p android-studio.meta
{ available = false; broken = false; unfree = true; unsupported = true; ... }
The following snippet is an example that uses this information to query
the availability information of all packages in nixpkgs, giving an
overview of all the packages currently marked as broken, etc.
{ pkgs }:
with import <nixpkgs/lib>;
let
mapPkgs =
let mapPkgs' = path: f: mapAttrs (n: v:
let result = builtins.tryEval (v ? meta); in
if !result.success then {} else
if isDerivation v then f (path ++ [n]) v else
if isAttrs v && v.recurseForDerivations or false then mapPkgs' (path ++ [n]) f v else
{}
);
in mapPkgs' [];
getMeta = path: drv:
if drv.meta ? available then
let meta = {
pkg = concatStringsSep "." path;
inherit (drv.meta) broken unfree unsupported insecure;
};
in builtins.trace meta.pkg meta
else {};
metaToList = attrs: flatten (map (v: if v ? pkg then v else metaToList v) (attrValues attrs));
in metaToList (mapPkgs getMeta pkgs)