Make build-subrepos.yml a reusable workflow.

Do not run on pull requests, rather have installers-conda.yml run on limited PRs and call build-subrepos.yml.

build-subrepos.yml will run on push to master if relevant files have changed, providing caches for any PR based off of master. PRs that trigger the installer workflow will trigger build-subrepos from within the installer workflow, ensuring that it is completed before the build installers step. If caches already exist and the subrepos do not need to be rebuilt, build-subrepos should complete rapidly.

.github/workflows/build-subrepos.yml

@@ -6,10 +6,7 @@ on:
       - '**.gitrepo'
       - '.github/workflows/build-subrepos.yml'
 
-  pull_request:
-    paths:
-      - '**.gitrepo'
-      - '.github/workflows/build-subrepos.yml'
+  workflow_call:
 
   workflow_dispatch:
 

.github/workflows/installers-conda.yml

@@ -6,7 +6,6 @@ on:
     paths:
       - 'installers-conda/**'
       - '.github/workflows/installers-conda.yml'
-      - '.github/workflows/build-subrepos.yml'
       - 'requirements/*.yml'
       - 'MANIFEST.in'
 
@@ -86,11 +85,18 @@ jobs:
         echo "target_platform=[$target_platform]" >> $GITHUB_OUTPUT
         echo "include=[$include]" >> $GITHUB_OUTPUT
 
+  build-subrepos:
+    name: Build Subrepos
+    if: github.event_name == 'pull_request' || github.event == 'schedule' || (github.event_name == 'workflow_dispatch' && ! inputs.pre)
+    uses: ./.github/workflows/build-subrepos.yml
+
   build-installers:
     name: Build installer for ${{ matrix.target-platform }} Python-${{ matrix.python-version }}
+    if: ${{ ! failure() && ! cancelled() }}
     runs-on: ${{ matrix.os }}
     needs:
       - build-matrix
+      - build-subrepos
     strategy:
       fail-fast: false
       matrix: