Update CompatHelper.yml

Author: evetion

.github/workflows/CompatHelper.yml

@@ -3,14 +3,48 @@ on:
   schedule:
     - cron: 0 0 * * *
   workflow_dispatch:
+permissions:
+  contents: write
+  pull-requests: write
 jobs:
   CompatHelper:
     runs-on: ubuntu-latest
     steps:
-      - name: Pkg.add("CompatHelper")
-        run: julia -e 'using Pkg; Pkg.add("CompatHelper")'
-      - name: CompatHelper.main()
+      - name: Check if Julia is already available in the PATH
+        id: julia_in_path
+        run: which julia
+        continue-on-error: true
+      - name: Install Julia, but only if it is not already available in the PATH
+        uses: julia-actions/setup-julia@v2
+        with:
+          version: '1'
+          arch: ${{ runner.arch }}
+        if: steps.julia_in_path.outcome != 'success'
+      - name: "Add the General registry via Git"
+        run: |
+          import Pkg
+          ENV["JULIA_PKG_SERVER"] = ""
+          Pkg.Registry.add("General")
+        shell: julia --color=yes {0}
+      - name: "Install CompatHelper"
+        run: |
+          import Pkg
+          name = "CompatHelper"
+          uuid = "aa819f21-2bde-4658-8897-bab36330d9b7"
+          version = "3"
+          Pkg.add(; name, uuid, version)
+        shell: julia --color=yes {0}
+      - name: "Run CompatHelper"
+        run: |
+          import CompatHelper
+          CompatHelper.main()
+        shell: julia --color=yes {0}
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # This repo uses Documenter, so we can reuse our [Documenter SSH key](https://documenter.juliadocs.org/stable/man/hosting/walkthrough/).
+          # If we didn't have one of those setup, we could configure a dedicated ssh deploy key `COMPATHELPER_PRIV` following https://juliaregistries.github.io/CompatHelper.jl/dev/#Creating-SSH-Key.
+          # Either way, we need an SSH key if we want the PRs that CompatHelper creates to be able to trigger CI workflows themselves.
+          # That is because GITHUB_TOKEN's can't trigger other workflows (see https://docs.github.com/en/actions/security-for-github-actions/security-guides/automatic-token-authentication#using-the-github_token-in-a-workflow).
+          # Check if you have a deploy key setup using these docs: https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/reviewing-your-deploy-keys.
           COMPATHELPER_PRIV: ${{ secrets.DOCUMENTER_KEY }}
-        run: julia -e 'using CompatHelper; CompatHelper.main()'
+          # COMPATHELPER_PRIV: ${{ secrets.COMPATHELPER_PRIV }}