Fix Spack CI by installing into builtin repo

- Copy package into spack/var/spack/repos/builtin/packages/mfc/
- Avoid external repo creation which has CMakePackage import issues
- Use standard 'from spack.package import *' import pattern
- Builtin repo packages have CMakePackage available automatically

Author: sbryngelson

.github/workflows/spack.yml

@@ -34,18 +34,17 @@ jobs:
           . spack/share/spack/setup-env.sh
           spack compiler find
 
-      - name: Create Spack Repository
+      - name: Install Package into Spack
         run: |
           . spack/share/spack/setup-env.sh
-          spack repo create mfc-repo mfc
-          mkdir -p mfc-repo/spack_repo/mfc/packages/mfc
-          cp packaging/spack/package.py mfc-repo/spack_repo/mfc/packages/mfc/
-          spack repo add mfc-repo/spack_repo/mfc
+          # Copy package directly into Spack's builtin repo
+          mkdir -p spack/var/spack/repos/builtin/packages/mfc
+          cp packaging/spack/package.py spack/var/spack/repos/builtin/packages/mfc/
 
       - name: Run Spack Style Check
         run: |
           . spack/share/spack/setup-env.sh
-          spack style mfc-repo/spack_repo/mfc/packages/mfc/package.py
+          spack style spack/var/spack/repos/builtin/packages/mfc/package.py
 
       - name: Run Spack Audit
         run: |
@@ -79,13 +78,12 @@ jobs:
           . spack/share/spack/setup-env.sh
           spack compiler find
 
-      - name: Create Spack Repository
+      - name: Install Package into Spack
         run: |
           . spack/share/spack/setup-env.sh
-          spack repo create mfc-repo mfc
-          mkdir -p mfc-repo/spack_repo/mfc/packages/mfc
-          cp packaging/spack/package.py mfc-repo/spack_repo/mfc/packages/mfc/
-          spack repo add mfc-repo/spack_repo/mfc
+          # Copy package directly into Spack's builtin repo
+          mkdir -p spack/var/spack/repos/builtin/packages/mfc
+          cp packaging/spack/package.py spack/var/spack/repos/builtin/packages/mfc/
 
       - name: Test Default Spec
         run: |

packaging/spack/package.py

@@ -3,7 +3,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
-from spack import *
+from spack.package import *
 
 
 class Mfc(CMakePackage):