fast-apt: actually bypass the Azure mirror (previous regex never matched)

.github/actions/fast-apt/action.yml

@@ -1,8 +1,9 @@
 name: Fast apt on arm64 runners
 description: >-
   Point Ubuntu package sources at the official ports mirror and set apt retry/timeout
-  defaults. The default Azure mirror took over 30 minutes for dependency installs on
-  arm64 runners (runs 40418762416, 40418762747). No-op on non-arm64 runners.
+  defaults. The default Azure mirror (azure.archive.ubuntu.com) took 15-34 minutes for
+  dependency installs on arm64 runners (runs 40418762416, 40418762747, 40482489505).
+  No-op on non-arm64 runners. Prints the resulting URIs so logs show it took effect.
 runs:
   using: composite
   steps:
@@ -11,7 +12,15 @@ runs:
         [ "$(dpkg --print-architecture)" = arm64 ] || exit 0
         printf 'Acquire::Retries "3";\nAcquire::http::Timeout "20";\nAcquire::https::Timeout "20";\n' \
           | sudo tee /etc/apt/apt.conf.d/99ci-fast >/dev/null
-        for f in /etc/apt/sources.list.d/ubuntu.sources; do
-          [ -f "$f" ] && sudo sed -i -E 's#^URIs:.*(azure\.)?ports\.ubuntu\.com.*#URIs: http://ports.ubuntu.com/ubuntu-ports#; s#^URIs:.*archive\.ubuntu\.com.*#URIs: http://ports.ubuntu.com/ubuntu-ports#' "$f"
-        done
-        [ -f /etc/apt/sources.list ] && sudo sed -i -E 's#https?://[a-z.]*(azure\.)?(ports|archive)\.ubuntu\.com/ubuntu(-ports)?#http://ports.ubuntu.com/ubuntu-ports#g' /etc/apt/sources.list || true
+        f=/etc/apt/sources.list.d/ubuntu.sources
+        if [ -f "$f" ]; then
+          # Replace the whole line: the runner may use azure.archive.ubuntu.com or mirror+file:.
+          sudo sed -i -E 's#^URIs:.*#URIs: http://ports.ubuntu.com/ubuntu-ports#' "$f"
+        fi
+        if [ -f /etc/apt/sources.list ]; then
+          sudo sed -i -E 's#https?://[a-z.]*(archive|ports)\.ubuntu\.com/ubuntu(-ports)?/?#http://ports.ubuntu.com/ubuntu-ports#g' /etc/apt/sources.list
+        fi
+        echo "apt sources now:"; grep -h -E '^(URIs:|deb )' /etc/apt/sources.list.d/*.sources /etc/apt/sources.list 2>/dev/null || true
+        if grep -rqs 'azure.archive.ubuntu.com' /etc/apt/sources.list /etc/apt/sources.list.d/ 2>/dev/null; then
+          echo "::warning::fast-apt: azure.archive.ubuntu.com is still configured"
+        fi

.github/workflows/files-image-actions.yml

@@ -26,6 +26,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - uses: actions/checkout@v7
+      - uses: ./.github/actions/fast-apt
       - name: Parse every utility and probe source
         run: python3 -c 'import ast, pathlib; [ast.parse(p.read_text(), filename=str(p)) for p in pathlib.Path("mseries/image-actions").glob("*.py")]'
       - name: Install native runtime and isolated display