diff --git a/FirebasePerformance/Tests/Unit/Timer/FPRCounterListTest.m b/FirebasePerformance/Tests/Unit/Timer/FPRCounterListTest.m
index d31cd61c6e1..00b2c78d38f 100644
--- a/FirebasePerformance/Tests/Unit/Timer/FPRCounterListTest.m
+++ b/FirebasePerformance/Tests/Unit/Timer/FPRCounterListTest.m
@@ -29,14 +29,18 @@ + (void)setUp {
   [super setUp];
   FIRPerformance *performance = [FIRPerformance sharedInstance];
   [performance setDataCollectionEnabled:YES];
+#ifdef UNSWIZZLE_AVAILABLE
   [[FPRClient sharedInstance] disableInstrumentation];
+#endif  // UNSWIZZLE_AVAILABLE
 }
 
 + (void)tearDown {
   [super tearDown];
   FIRPerformance *performance = [FIRPerformance sharedInstance];
   [performance setDataCollectionEnabled:NO];
+#ifdef UNSWIZZLE_AVAILABLE
   [[FPRClient sharedInstance] disableInstrumentation];
+#endif  // UNSWIZZLE_AVAILABLE
 }
 
 /** Validates counterlist object creation. */
diff --git a/scripts/build.sh b/scripts/build.sh
index 67e576ac990..15019bd184c 100755
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -110,10 +110,12 @@ source scripts/check_secrets.sh
 function RunXcodebuild() {
   echo xcodebuild "$@"
 
-  xcbeautify_cmd=(xcbeautify --renderer github-actions)
+  xcbeautify_cmd=(xcbeautify --renderer github-actions --disable-logging)
 
   result=0
-  xcodebuild "$@" | tee xcodebuild.log | "${xcbeautify_cmd[@]}" || result=$?
+  xcodebuild "$@" | tee xcodebuild.log | "${xcbeautify_cmd[@]}" \
+    && CheckUnexpectedFailures xcodebuild.log \
+    || result=$?
 
   if [[ $result == 65 ]]; then
     ExportLogs "$@"
@@ -122,7 +124,9 @@ function RunXcodebuild() {
     sleep 5
 
     result=0
-    xcodebuild "$@" | tee xcodebuild.log | "${xcbeautify_cmd[@]}" || result=$?
+    xcodebuild "$@" | tee xcodebuild.log | "${xcbeautify_cmd[@]}" \
+      && CheckUnexpectedFailures xcodebuild.log \
+      || result=$?
   fi
 
   if [[ $result != 0 ]]; then
@@ -138,6 +142,15 @@ function ExportLogs() {
   python "${scripts_dir}/xcresult_logs.py" "$@"
 }
 
+function CheckUnexpectedFailures() {
+  local log_file=$1
+
+  if grep -Eq "[1-9]\d* failures \([1-9]\d* unexpected\)" "$log_file"; then
+    echo "xcodebuild failed with unexpected failures." 1>&2
+    return 65
+  fi
+}
+
 if [[ "$xcode_major" -lt 15 ]]; then
   ios_flags=(
     -sdk 'iphonesimulator'