try

scripts/build_test.sh

@@ -45,7 +45,7 @@ do
     unexpected_failures=$(
         # First grep pattern corresponds to test failures, second pattern corresponds to test panics due to timeouts
         (grep "^--- FAIL" test.out | awk '{print $3}' || grep -E '^\s+Test.+ \(' test.out | awk '{print $1}') |
-        sed 's/^M$//' | sort -u | comm -23 - ./scripts/known_flakes.txt
+        sed 's/\r$//' | sort -u | comm -23 - ./scripts/known_flakes.txt
     )
     if [ -n "${unexpected_failures}" ]; then
         echo "Unexpected test failures: ${unexpected_failures}"