Merge 0b16518fff into 638ed79f9d

Add note on runner versions

README.md

@@ -19,16 +19,19 @@ See ["Caching dependencies to speed up workflows"](https://docs.github.com/en/ac
 
 The cache backend service has been rewritten from the ground up for improved performance and reliability. [actions/cache](https://github.com/actions/cache) now integrates with the new cache service (v2) APIs.
 
-The new service will gradually roll out as of **February 1st, 2025**. The legacy service will also be sunset on the same date. Changes in these release are **fully backward compatible**.
+The new service will gradually roll out as of **February 1st, 2025**. The legacy service will also be sunset on the same date. Changes in these releases are **fully backward compatible**.
 
 **We are deprecating some versions of this action**. We recommend upgrading to version `v4` or `v3` as soon as possible before **February 1st, 2025.** (Upgrade instructions below).
 
-If you are using pinned SHAs, please use the SHAs of versions `v4.2.0` or `v3.4.0`
+If you are using pinned SHAs, please use the SHAs of versions `v4.2.0` or `v3.4.0`.
 
 If you do not upgrade, all workflow runs using any of the deprecated [actions/cache](https://github.com/actions/cache) will fail.
 
 Upgrading to the recommended versions will not break your workflows.
 
+> **Additionally, if you are managing your own GitHub runners, you must update your runner version to `2.231.0` or newer to ensure compatibility with the new cache service.**  
+> Failure to update both the action version and your runner version may result in workflow failures after the migration date.
+
 Read more about the change & access the migration guide: [reference to the announcement](https://github.com/actions/cache/discussions/1510).
 
 ### v4

examples.md

@@ -25,6 +25,7 @@
 - [Node - Yarn](#node---yarn)
 - [Node - Yarn 2](#node---yarn-2)
 - [OCaml/Reason - esy](#ocamlreason---esy)
+- [OCaml/Reason - opam](#ocamlreason---opam)
 - [PHP - Composer](#php---composer)
 - [Python - pip](#python---pip)
   - [Simple example](#simple-example)
@@ -437,6 +438,30 @@ Esy allows you to export built dependencies and import pre-built dependencies.
       if: steps.restore-cache.outputs.cache-hit != 'true'
 ```
 
+## OCaml/Reason - opam
+
+This example requires you to have `opam.locked` file which you can generate with `opam lock .`.
+
+It's worth noting that even if lock file was change, it might be optimal to restore previous cache, so `hashFiles` in the key and if statement in "Save opam cache" step are optional.
+```yaml
+    - name: Restore opam cache
+      id: restore-cache
+      uses: actions/cache/restore@v4
+      with:
+        path: _opam
+        key: ${{ runner.os }}-opam-${{ hashFiles('opam.locked') }}
+
+    - name: Install dependencies
+      run: opam install . --locked --deps-only -y
+
+    - name: Save opam cache
+      if: steps.restore-cache.outputs.cache-hit != 'true'
+      uses: actions/cache/save@v4
+      with:
+        path: _opam
+        key: ${{ steps.restore-cache.outputs.cache-primary-key }}
+```
+
 ## PHP - Composer
 
 ```yaml