Zephyr autogen auto-update fixes

.github/workflows/zephyr-autogen-pr.yml

@@ -71,16 +71,41 @@ jobs:
             echo "changed=true" >> "$GITHUB_OUTPUT"
             git status --short -- 'ports/zephyr-cp/boards/**/autogen_board_info.toml'
           fi
+      - name: Find existing open autogen PR
+        id: pr
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          pr=$(gh pr list --state open --head zephyr-autogen-board-info --json number --jq '.[0].number // empty')
+          echo "number=$pr" >> "$GITHUB_OUTPUT"
+          if [ -n "$pr" ]; then
+            echo "Found existing open autogen PR #$pr; will push to it."
+          fi
+      - name: Delete stale autogen branch
+        # A new pull request cannot be created from a head branch that already
+        # had one. If the previous autogen PR was closed without merging, the
+        # branch lingers on; delete it so create-pull-request can start over.
+        if: steps.diff.outputs.changed == 'true' && steps.pr.outputs.number == ''
+        run: |
+          if git ls-remote --heads origin zephyr-autogen-board-info | grep -q zephyr-autogen-board-info; then
+            git push origin --delete zephyr-autogen-board-info
+          fi
       - name: Create PR
         if: steps.diff.outputs.changed == 'true'
         uses: peter-evans/create-pull-request@v8
         with:
           add-paths: ports/zephyr-cp/boards/**/autogen_board_info.toml
           commit-message: Regenerate zephyr-cp autogen_board_info.toml files
           title: Regenerate zephyr-cp autogenerated board info
+          # create-pull-request pushes to the branch of an existing open PR,
+          # so a still-open autogen PR is updated in place instead of spawning
+          # a second one.
           body: |
             The `autogen_board_info.toml` files changed after building all zephyr-cp
             boards on `main`. Created by the "Update Zephyr autogenerated files"
             workflow.
+
+            Based on commit: ${{ github.sha }}
+            Workflow run: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
           branch: zephyr-autogen-board-info
           delete-branch: true

ports/zephyr-cp/cptools/build_circuitpython.py

@@ -331,13 +331,19 @@ def determine_enabled_modules(board_info, portdir, srcdir):
         enabled_modules.add("ssl")
         module_reasons["ssl"] = "Zephyr networking enabled"
 
-    for port_module in (portdir / "bindings").iterdir():
+    # Iterate the shared-bindings directory in a stable (sorted) order. Several
+    # modules can enable the same reverse dependency, and the "reason" comment
+    # recorded in autogen_board_info.toml belongs to whichever module enabled it
+    # first. Directory iteration order is filesystem dependent (it differs
+    # between machines and CI runners), so an unsorted walk made the generated
+    # comments - and therefore the committed toml files - change between builds.
+    for port_module in sorted((portdir / "bindings").iterdir(), key=lambda x: x.name):
         if not board_info.get(port_module.name, False):
             continue
         enabled_modules.add(port_module.name)
         module_reasons[port_module.name] = f"Zephyr board has {port_module.name}"
 
-    for shared_module in (srcdir / "shared-bindings").iterdir():
+    for shared_module in sorted((srcdir / "shared-bindings").iterdir(), key=lambda x: x.name):
         if not board_info.get(shared_module.name, False) or not shared_module.glob("*.c"):
             continue
         enabled_modules.add(shared_module.name)