spring-framework 4.1.x 导入 IDEA 报错，怎么解决？

1. OS: macOS Catalina
2. 源代码地址：https://github.com/spring-projects/spring-framework/tree/4.1.x
3. 源代码分支：4.1.x
4. 源代码下载到本地后，根据文档 https://github.com/spring-projects/spring-framework/blob/4.1.x/import-into-idea.md 执行命令：./gradlew cleanIdea :spring-oxm:compileTestJava，报错如下：

$ ./gradlew cleanIdea :spring-oxm:compileTestJava
:buildSrc:compileJava UP-TO-DATE
:buildSrc:compileGroovy UP-TO-DATE
:buildSrc:processResources UP-TO-DATE
:buildSrc:classes UP-TO-DATE
:buildSrc:jar UP-TO-DATE
:buildSrc:assemble UP-TO-DATE
:buildSrc:compileTestJava UP-TO-DATE
:buildSrc:compileTestGroovy UP-TO-DATE
:buildSrc:processTestResources UP-TO-DATE
:buildSrc:testClasses UP-TO-DATE
:buildSrc:test UP-TO-DATE
:buildSrc:check UP-TO-DATE
:buildSrc:build UP-TO-DATE

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'spring'.
> Could not resolve all dependencies for configuration ':classpath'.
   > Could not resolve org.springframework.build.gradle:propdeps-plugin:0.0.7.
     Required by:
         :spring:4.1.10.BUILD-SNAPSHOT
      > Could not GET 'https://repo.spring.io/plugins-release/org/springframework/build/gradle/propdeps-plugin/0.0.7/propdeps-plugin-0.0.7.pom'. Received status code 401 from server:
   > Could not resolve org.asciidoctor:asciidoctor-gradle-plugin:0.7.0.
     Required by:
         :spring:4.1.10.BUILD-SNAPSHOT
      > Could not HEAD 'https://repo.spring.io/plugins-release/org/asciidoctor/asciidoctor-gradle-plugin/0.7.0/asciidoctor-gradle-plugin-0.7.0.pom'. Received status code 401 from server:
   > Could not resolve io.spring.gradle:docbook-reference-plugin:0.3.1.
     Required by:
         :spring:4.1.10.BUILD-SNAPSHOT
      > Could not GET 'https://repo.spring.io/plugins-release/io/spring/gradle/docbook-reference-plugin/0.3.1/docbook-reference-plugin-0.3.1.pom'. Received status code 401 from server:
   > Could not resolve ws.antonov.gradle.plugins:gradle-plugin-protobuf:0.9.1.
     Required by:
         :spring:4.1.10.BUILD-SNAPSHOT
      > Could not HEAD 'https://repo.spring.io/plugins-release/ws/antonov/gradle/plugins/gradle-plugin-protobuf/0.9.1/gradle-plugin-protobuf-0.9.1.pom'. Received status code 401 from server:

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 11.139 secs

1. 看报错信息，大概明白从 https://repo.spring.io 下载依赖需要用户名、密码等认证信息。我应该怎么修改构建配置文件呢？