final version of ci spec

.drone.yml

@@ -9,5 +9,5 @@ steps:
       #- nix-shell --pure --run "dart --version"
       - nix-shell --pure --run "flutter build apk --split-per-abi"
     environment:
-      NIX_PATH: "nixpkgs=/nix/var/nix/profiles/per-user/root/channels/nixos"
+      NIX_PATH: "unstable=/nix/var/nix/profiles/per-user/root/channels/unstable"
       NIXPKGS_ALLOW_UNFREE: 1

shell.nix

@@ -1,16 +1,15 @@
-{ pkgs ? import <nixpkgs> { config.android_sdk.accept_license = true; } }:
+{ pkgs ? import <unstable> { config.android_sdk.accept_license = true; } }:
 
 let
-  unstable = import (fetchTarball "https://nixos.org/channels/nixpkgs-unstable/nixexprs.tar.xz") {};
-
   androidComposition = pkgs.androidenv.composeAndroidPackages {
     toolsVersion = "26.1.1";
     platformToolsVersion = "33.0.2";
-    buildToolsVersions = [ "33.0.0" ];
+    buildToolsVersions = [ "30.0.3" ];
+    platformVersions = [ "31" "30" "29" ];
   };
 in
 pkgs.mkShell {
   ANDROID_HOME= "${androidComposition.androidsdk}/libexec/android-sdk";
   ANDROID_SDK_ROOT = "${androidComposition.androidsdk}/libexec/android-sdk";
-  nativeBuildInputs = with pkgs; [ unstable.flutter openjdk11_headless ];
+  nativeBuildInputs = with pkgs; [ flutter openjdk11_headless ];
 }