ci: replace ci.nix with build of bootstrapZip

bootstrapZip builds all derivations transitively.

.github/workflows/cachix.yml

@@ -1,4 +1,4 @@
-name: Build ci.nix and push to cachix
+name: Build bootstrap packages and push to cachix
 on:
   pull_request:
   push:
@@ -21,5 +21,11 @@ jobs:
           name: nix-on-droid
           signingKey: "${{ secrets.CACHIX_SIGNING_KEY }}"
 
-      - name: Build ci.nix
-        run: nix-build ci.nix
+      - name: Build bootstrap zip
+        run: |
+          nix \
+            --log-format bar-with-logs \
+            --option keep-going true \
+            --show-trace \
+            build .#bootstrapZip \
+            --impure

ci.nix

@@ -1,26 +0,0 @@
-# Copyright (c) 2019-2020, see AUTHORS. Licensed under MIT License, see LICENSE.
-
-with import <nixpkgs> { };
-
-with lib;
-
-let
-  pkgs = (import ./pkgs { }) // { recurseForDerivations = true; };
-  isCacheable = p: !(p.preferLocalBuild or false);
-  shouldRecurseForDerivations = p: isAttrs p && p.recurseForDerivations or false;
-
-  flattenPkgs = s:
-    let
-      f = p:
-        if shouldRecurseForDerivations p then flattenPkgs p
-        else if isDerivation p then [ p ]
-        else [ ];
-    in
-    concatMap f (attrValues s);
-
-  cachePkgs = filter isCacheable (flattenPkgs pkgs);
-
-  outputsOf = p: map (o: p.${o}) p.outputs;
-in
-
-concatMap outputsOf cachePkgs