properly implement custom compiler inputs

.github/actions/nimbus-build-system/action.yml

@@ -11,8 +11,10 @@ inputs:
     default: "amd64"
   nim_version:
     description: "Nim version"
-    # FIXME: change this once https://github.com/nim-lang/Nim/issues/23214 gets upstreamed/backported
-    default: "f45bdea94ac4ed9a9bae03426275456aeb0cab2a"
+    default: "version-1-6"
+  nim_repo:
+    description: "Nim compiler repository"
+    default: "https://github.com/nim-lang/Nim"
   shell:
     description: "Shell to run commands in"
     default: "bash --noprofile --norc -e -o pipefail"
@@ -164,7 +166,7 @@ runs:
     # FIXME: drop this once https://github.com/nim-lang/Nim/issues/23214 gets upstreamed/backported
     - name: Set NIM_REPO
       shell: ${{ inputs.shell }} {0}
-      run: echo "NIM_REPO='https://github.com/gmega/Nim'" >> ${GITHUB_ENV}
+      run: echo "NIM_REPO=${{ inputs.nim_repo }}" >> ${GITHUB_ENV}
 
     - name: Build Nim and Codex dependencies
       shell: ${{ inputs.shell }} {0}

.github/workflows/ci.yml

@@ -9,6 +9,7 @@ env:
   cache_nonce: 0 # Allows for easily busting actions/cache caches
   # FIXME: change this once https://github.com/nim-lang/Nim/issues/23214 gets upstreamed/backported
   nim_version: f45bdea94ac4ed9a9bae03426275456aeb0cab2a
+  nim_repo: "https://github.com/gmega/Nim"
 jobs:
   build:
     strategy:
@@ -59,6 +60,7 @@ jobs:
           os: ${{ matrix.os }}
           shell: ${{ matrix.shell }}
           nim_version: ${{ env.nim_version }}
+          nim_repo: ${{ env.nim_repo}}
 
       ## Part 1 Tests ##
       - name: Unit tests