Reference nixpkgs config from linux|macos-nixpkgs

Author: aherrmann

.bazelrc

@@ -12,6 +12,8 @@ test --test_env=LANG=C.UTF-8 --test_env=LOCALE_ARCHIVE
 
 # Platform / Toolchain Selection
 # ------------------------------
+build:linux-nixpkgs --config=nixpkgs
+build:macos-nixpkgs --config=nixpkgs
 build:nixpkgs --host_platform=@io_tweag_rules_nixpkgs//nixpkgs/platforms:host
 # Use this configuration when targeting Windows. Eventually this will
 # no longer be required:

.github/workflows/workflow.yaml

@@ -21,10 +21,13 @@ jobs:
           nix_path: nixpkgs=./nixpkgs/default.nix
       - name: Configure
         run: |
-          [[ ${{ matrix.os }} == macos ]] && EXTRA_CONFIG=--config=macos-nixpkgs
+          case ${{ matrix.os }} in
+            macos) BUILD_CONFIG=macos-nixpkgs;;
+            ubuntu) BUILD_CONFIG=linux-nixpkgs;;
+          esac
           cat >.bazelrc.local <<EOF
           common --config=ci
-          build --config=nixpkgs $EXTRA_CONFIG
+          build --config=$BUILD_CONFIG
           EOF
       - name: Check Bazel version
         run: |