From f83bfa17ff878a6689b875353df7200ab2d30053 Mon Sep 17 00:00:00 2001
From: Kris Austin <kris.austin@gmail.com>
Date: Tue, 22 Sep 2026 13:41:30 -0500
Subject: [PATCH] ci: keep older compiler cache entries when the save wrote
 nothing (#15828)

#15668 saves the compiler cache on cancelled and failed builds and then
drops the older entries for the leg on the ref. actions/cache/save only
warns when its tar fails, so a cancelled build whose ccache directory
was still being written saved nothing, the drop ran anyway and deleted
the leg's last good entry. The next run on main restored nothing and
compiled cold, and so did every PR that restored in the gap. Run
35405244634 (Flatpak x86_64, 2026-09-18) did this to
ccache-Flatpak-x86_64-35397824860-1; between 13 and 18 September 9 of
87 cancelled main build jobs did the same.

Look the new entry up before deleting anything, and keep the older ones
when it is not there.
---
 .github/workflows/build_all.yml  | 8 ++++++++
 .github/workflows/build_orca.yml | 7 +++++++
 2 files changed, 15 insertions(+)

diff --git a/.github/workflows/build_all.yml b/.github/workflows/build_all.yml
index ed106ec65e..24317b0add 100644
--- a/.github/workflows/build_all.yml
+++ b/.github/workflows/build_all.yml
@@ -413,6 +413,14 @@ jobs:
         GH_TOKEN: ${{ github.token }}
       run: |
         api="$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/actions/caches"
+        # The save step reports success even when its tar failed, so keep
+        # the older entries unless the new one is listed.
+        if ! curl -sSf -H "Authorization: Bearer $GH_TOKEN" \
+            "$api?ref=$GITHUB_REF&key=$CCACHE_ENTRY" \
+            | jq -e --arg entry "$CCACHE_ENTRY" 'any(.actions_caches[]; .key == $entry)' > /dev/null; then
+          echo "$CCACHE_ENTRY was not saved; keeping the older entries."
+          exit 0
+        fi
         curl -sSf -H "Authorization: Bearer $GH_TOKEN" \
           "$api?ref=$GITHUB_REF&key=ccache-$CCACHE_LEG-&per_page=100" \
           | jq -r --arg prefix "ccache-$CCACHE_LEG-" --argjson run "$GITHUB_RUN_ID" \
diff --git a/.github/workflows/build_orca.yml b/.github/workflows/build_orca.yml
index 85458615b4..2ea72d0773 100644
--- a/.github/workflows/build_orca.yml
+++ b/.github/workflows/build_orca.yml
@@ -798,6 +798,13 @@ jobs:
         env:
           GH_TOKEN: ${{ github.token }}
         run: |
+          # The save step reports success even when its tar failed, so keep
+          # the older entries unless the new one is listed.
+          if ! gh cache list --ref "$GITHUB_REF" --key "$CCACHE_ENTRY" --json key \
+              | jq -e --arg entry "$CCACHE_ENTRY" 'any(.[]; .key == $entry)' > /dev/null; then
+            echo "$CCACHE_ENTRY was not saved; keeping the older entries."
+            exit 0
+          fi
           gh cache list --ref "$GITHUB_REF" --key "ccache-$CCACHE_LEG-" --limit 100 --json id,key \
             | jq -r --arg prefix "ccache-$CCACHE_LEG-" --argjson run "$GITHUB_RUN_ID" \
                 '.[] | select((.key | ltrimstr($prefix) | split("-")[0] | tonumber?) < $run) | .id' \