[remove nixpkgs] enable fallback for packages not in binary store

Author: savil

internal/boxcli/featureflag/remove_nixpkgs.go

@@ -4,4 +4,4 @@ package featureflag
 // It leverages the search index to directly map <package>@<version> to
 // the /nix/store/<hash>-<package>-<version> that can be fetched from
 // cache.nixpkgs.org.
-var RemoveNixpkgs = disable("REMOVE_NIXPKGS")
+var RemoveNixpkgs = enable("REMOVE_NIXPKGS")

internal/shellgen/tmpl/flake_remove_nixpkgs.nix.tmpl

@@ -17,6 +17,14 @@
    }:
       let
         pkgs = nixpkgs.legacyPackages.{{ .System }};
+        {{- range .FlakeInputs }}
+        {{- if .IsNixpkgs }}
+        {{.PkgImportName}} = (import {{.Name}} {
+          system = "{{ $.System }}";
+          config.allowUnfree = true;
+        });
+        {{- end }}
+        {{- end }}
       in
       {
         devShells.{{ .System }}.default = pkgs.mkShell {