diff --git a/diff-sha.sh b/diff-sha.sh
index 434f2899c6b..812c105bfa1 100644
--- a/diff-sha.sh
+++ b/diff-sha.sh
@@ -57,6 +57,7 @@ else
 fi
 
 if [[ -z $GITHUB_BASE_REF ]]; then
+  echo "Running on a push event..."
   TARGET_BRANCH=${GITHUB_REF/refs\/heads\//} && exit_status=$? || exit_status=$?
   CURRENT_BRANCH=$TARGET_BRANCH && exit_status=$? || exit_status=$?
 
@@ -64,7 +65,8 @@ if [[ -z $GITHUB_BASE_REF ]]; then
     PREVIOUS_SHA=$GITHUB_EVENT_BEFORE
 
     if [[ -z "$PREVIOUS_SHA" || "$PREVIOUS_SHA" == "0000000000000000000000000000000000000000" ]]; then
-      PREVIOUS_SHA=$(git rev-parse "$(git branch -r --sort=-committerdate | head -1)")
+      echo "::debug::First commit detected"
+      PREVIOUS_SHA=$(git rev-parse "$(git branch -r --sort=-committerdate | head -1 | xargs)")
     fi
 
     if [[ "$PREVIOUS_SHA" == "$CURRENT_SHA" ]]; then
@@ -89,6 +91,7 @@ if [[ -z $GITHUB_BASE_REF ]]; then
     exit 1
   fi
 else
+  echo "Running on a pull request event..."
   TARGET_BRANCH=$GITHUB_BASE_REF
   CURRENT_BRANCH=$GITHUB_HEAD_REF
 
diff --git a/get-base-sha.sh b/get-base-sha.sh
index c2fcee3c283..3b6efb024c3 100644
--- a/get-base-sha.sh
+++ b/get-base-sha.sh
@@ -25,7 +25,8 @@ elif [[ "$INPUT_SINCE_LAST_REMOTE_COMMIT" == "true" ]]; then
   LAST_REMOTE_COMMIT="$GITHUB_EVENT_BEFORE"
 
   if [[ -z "$LAST_REMOTE_COMMIT" || "$LAST_REMOTE_COMMIT" == "0000000000000000000000000000000000000000" ]]; then
-    LAST_REMOTE_COMMIT=$(git rev-parse "$(git branch -r --sort=-committerdate | head -1)")
+    echo "::debug::First commit detected"
+    LAST_REMOTE_COMMIT=$(git rev-parse "$(git branch -r --sort=-committerdate | head -1 | xargs)")
   fi
   if [[ "$INPUT_SHA" == "$LAST_REMOTE_COMMIT" ]]; then
     LAST_REMOTE_COMMIT=$(git rev-parse "$INPUT_SHA^1")