CI: Fix ARM64 apt retry to detect partial failures

The previous retry mechanism had a critical flaw: apt update returns
exit code 0 even when some files fail to download, as long as SOME
updates succeed. This caused the retry loop to break immediately even
when errors like "Failed to fetch" occurred.

Author: jserv

.github/workflows/main.yml

@@ -303,17 +303,20 @@ jobs:
         # No 'sudo' is available
         install: |
           # Retry apt update with delays to handle mirror sync issues
+          # apt update returns 0 even with partial failures, so check logs
           for i in 1 2 3 4 5; do
-            if apt update -qq --allow-releaseinfo-change 2>&1 | tee /tmp/apt-update.log; then
+            apt update -qq --allow-releaseinfo-change 2>&1 | tee /tmp/apt-update.log
+            if ! grep -q "Failed to fetch\|Hash Sum mismatch" /tmp/apt-update.log; then
+              echo "apt update succeeded on attempt $i"
               break
             fi
-            echo "apt update attempt $i failed, waiting 10 seconds..."
-            sleep 10
+            if [ $i -lt 5 ]; then
+              echo "apt update attempt $i had errors, waiting 10 seconds before retry..."
+              sleep 10
+            else
+              echo "Warning: apt update still has errors after 5 attempts, proceeding anyway..."
+            fi
           done
-          # Show errors if apt update failed
-          if grep -q "Failed to fetch\|Hash Sum mismatch" /tmp/apt-update.log; then
-            echo "Warning: apt update had issues but continuing..."
-          fi
           apt install -yqq make git curl wget clang libsdl2-dev libsdl2-mixer-dev lsb-release software-properties-common gnupg bc
           which wget || echo "WARNING: wget not found after installation"
         # FIXME: gcc build fails on Aarch64/Linux hosts
@@ -324,11 +327,14 @@ jobs:
           # Verify and install wget if needed (workaround for install step issues)
           if ! command -v wget > /dev/null 2>&1; then
             for i in 1 2 3; do
-              if apt update -qq --allow-releaseinfo-change; then
+              apt update -qq --allow-releaseinfo-change 2>&1 | tee /tmp/apt-update-wget.log
+              if ! grep -q "Failed to fetch\|Hash Sum mismatch" /tmp/apt-update-wget.log; then
                 break
               fi
-              echo "apt update retry $i failed, waiting 10 seconds..."
-              sleep 10
+              if [ $i -lt 3 ]; then
+                echo "apt update retry $i had errors, waiting 10 seconds..."
+                sleep 10
+              fi
             done
             apt install -yqq wget
           fi