From 3ec2440bd1d1763b3dc92a673e2d93746657b816 Mon Sep 17 00:00:00 2001
From: James Griffin <james@unsupervised.ca>
Date: Thu, 20 Aug 2026 15:16:25 -0300
Subject: [PATCH] Probe which actions/cache variant can reach the v2 cache
 service
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The first probe answered the original question and raised a better one.
ACTIONS_CACHE_URL is unset but ACTIONS_RESULTS_URL points at
gitea-unsupervised-git-http.gitea.svc.cluster.local:3000, so the runner
does serve a cache — the v2 service, not v1. actions/cache resolves to
v4.3.0, which can speak v2, but only when ACTIONS_CACHE_SERVICE_V2 is
set, and the runner does not set it. So the action falls back to v1,
finds no endpoint, and trips its GHES gate on the way past.

Three variants to find one that reaches the service that is already
running: v4 with the flag forced, v6.1.0 which is current, and v6 with
the flag. Any that saves is a fix that lives in this repository.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uw545F1vveNJKjzLxdi2ks
---
 .gitea/workflows/cache-probe.yml | 38 ++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/.gitea/workflows/cache-probe.yml b/.gitea/workflows/cache-probe.yml
index 066404d..036102c 100644
--- a/.gitea/workflows/cache-probe.yml
+++ b/.gitea/workflows/cache-probe.yml
@@ -51,3 +51,41 @@ jobs:
         run: |
           echo "runner.arch = ${{ runner.arch }}"
           echo "runner.os   = ${{ runner.os }}"
+
+  # The first probe showed ACTIONS_CACHE_URL unset but ACTIONS_RESULTS_URL set,
+  # i.e. the runner serves the v2 cache service and not v1. actions/cache v4.3
+  # can speak v2, but only when ACTIONS_CACHE_SERVICE_V2 is set, and it is not.
+  # These three variants test the ways round that.
+  variant-v4-flag:
+    name: cache@v4 + ACTIONS_CACHE_SERVICE_V2
+    runs-on: ubuntu-latest
+    env:
+      ACTIONS_CACHE_SERVICE_V2: "true"
+    steps:
+      - run: mkdir -p /tmp/probe && head -c 1048576 /dev/urandom > /tmp/probe/blob
+      - uses: actions/cache@v4
+        with:
+          path: /tmp/probe
+          key: probe-v4flag-${{ github.run_id }}
+
+  variant-v6:
+    name: cache@v6
+    runs-on: ubuntu-latest
+    steps:
+      - run: mkdir -p /tmp/probe && head -c 1048576 /dev/urandom > /tmp/probe/blob
+      - uses: actions/cache@v6
+        with:
+          path: /tmp/probe
+          key: probe-v6-${{ github.run_id }}
+
+  variant-v6-flag:
+    name: cache@v6 + ACTIONS_CACHE_SERVICE_V2
+    runs-on: ubuntu-latest
+    env:
+      ACTIONS_CACHE_SERVICE_V2: "true"
+    steps:
+      - run: mkdir -p /tmp/probe && head -c 1048576 /dev/urandom > /tmp/probe/blob
+      - uses: actions/cache@v6
+        with:
+          path: /tmp/probe
+          key: probe-v6flag-${{ github.run_id }}