diff --git a/jenkins/Jenkinsfile.ai-game-creator-shell-macos-build b/jenkins/Jenkinsfile.ai-game-creator-shell-macos-build
index 6e57007b8..71146a824 100644
--- a/jenkins/Jenkinsfile.ai-game-creator-shell-macos-build
+++ b/jenkins/Jenkinsfile.ai-game-creator-shell-macos-build
@@ -43,6 +43,9 @@ pipeline {
         // 目的是防止把开发 checkout 当成 Jenkins workspace。
         sh '''
           set -eu
+          # 手工「立即构建」时可选参数可能根本没定义（不是空值），先统一成空串/默认值，
+          # 否则 set -u 会让 Checkout 直接失败。
+          SOURCE_BRANCH="${SOURCE_BRANCH:-master}"
           if [ -n "${AGC_AGENT_ROOT:-}" ]; then
             case "$WORKSPACE" in "$AGC_AGENT_ROOT"/workspace/*) ;; *) echo "拒绝非专用 Agent 工作区：$WORKSPACE"; exit 1;; esac
           else
@@ -54,6 +57,10 @@ pipeline {
         withCredentials([sshUserPrivateKey(credentialsId: env.GIT_REMOTE_CREDENTIAL_ID, keyFileVariable: 'GIT_SSH_KEY', usernameVariable: 'GIT_SSH_USER')]) {
           sh '''
             set -eu
+            # 同上：可选参数在「立即构建」里可能是未定义变量，统一兜底再使用。
+            SOURCE_BRANCH="${SOURCE_BRANCH:-master}"
+            COMMIT_HASH="${COMMIT_HASH:-}"
+            SKIP_IF_SUPERSEDED="${SKIP_IF_SUPERSEDED:-false}"
             export GIT_SSH_COMMAND="ssh -i \\"$GIT_SSH_KEY\\" -o IdentitiesOnly=yes -o StrictHostKeyChecking=yes"
             if [ ! -d .git ]; then
               git init