我尝试根据他们的指令运行lenskit-hello。当我运行./gradlew build时，我收到错误

(base) Briennas-MBP:lenskit-hello-master briennakh$ ./gradlew build
:compileJava

FAILURE: Build failed with an exception.

* What went wrong:
Could not resolve all dependencies for configuration ':compileClasspath'.
> Could not resolve org.lenskit:lenskit-all:3.0-M3.
  Required by:
      :lenskit-hello-master 4.50.57 AM:unspecified
   > Could not resolve org.lenskit:lenskit-all:3.0-M3.
      > Could not get resource 'https://repo1.maven.org/maven2/org/lenskit/lenskit-all/3.0-M3/lenskit-all-3.0-M3.pom'.
         > Could not GET 'https://repo1.maven.org/maven2/org/lenskit/lenskit-all/3.0-M3/lenskit-all-3.0-M3.pom'.
            > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   > Could not resolve org.lenskit:lenskit-all:3.0-M3.
      > Could not get resource 'https://jcenter.bintray.com/org/lenskit/lenskit-all/3.0-M3/lenskit-all-3.0-M3.pom'.
         > Could not GET 'https://jcenter.bintray.com/org/lenskit/lenskit-all/3.0-M3/lenskit-all-3.0-M3.pom'.
            > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

* 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: 4.009 secs

我在MacOS莫哈韦10.14.6上使用的是Java 1.8.0_241（而且只安装了这一个）。我已经安装了最新的安全更新，然后重新启动了我的电脑。我已经在我的常规WiFi和手机的热点上尝试了这一点。
我按照已接受答案here中的说明，从https://repo1.maven.org/maven2/org/lenskit/lenskit-all/3.0-M2/lenskit-all-3.0-M2.pom和https://oss.sonatype.org/content/repositories/snapshots/org/lenskit/lenskit-all/3.0-M2/lenskit-all-3.0-M2.pom下载安全证书，并通过以下命令将它们添加到密钥库中（仅显示两个中的一个）：

keytool -import -alias maven -file /Users/briennakh/Downloads/maven.cer -keystore 
/Library/Java/JavaVirtualMachines/jdk1.8.0_241.jdk/Contents/Home/jre/lib/security/cacerts

如果我查一下

keytool -list -keystore /Library/Java/JavaVirtualMachines/jdk1.8.0_241.jdk/Contents/Home/jre/lib/security/cacerts | grep maven

它显示我的证书已经添加，maven, Mar 17, 2020, trustedCertEntry，但是我在运行./gradlew build时仍然得到同样的错误？
我还检查了openssl x509 -in /Users/briennakh/Downloads/maven.pem -text以确保证书看起来正常。