Я пытался собрать CAS версии 5.3.x и столкнулся с проблемой запуска Gradle build.
> Task :support:cas-server-support-duo-core:compileJava FAILED FAILURE: Build failed with an exception. * What went wrong: Could not resolve all files for configuration ':support:cas-server-support-duo-core:compileClasspath'. > Could not resolve net.unicon.iam:duo-client:0.2.2. Required by: project :support:cas-server-support-duo-core > Could not resolve net.unicon.iam:duo-client:0.2.2. > Could not get resource 'https://jcenter.bintray.com/net/unicon/iam/duo-client/0.2.2/duo-client-0.2.2.pom'. > Could not GET 'https://jcenter.bintray.com/net/unicon/iam/duo-client/0.2.2/duo-client-0.2.2.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 net.unicon.iam:duo-client:0.2.2. > Could not get resource 'https://dl.bintray.com/uniconiam/maven/net/unicon/iam/duo-client/0.2.2/duo-client-0.2.2.pom'. > Could not GET 'https://dl.bintray.com/uniconiam/maven/net/unicon/iam/duo-client/0.2.2/duo-client-0.2.2.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 net.unicon.iam:duo-client:0.2.2. > Could not get resource 'https://jcenter.bintray.com/net/unicon/iam/duo-client/0.2.2/duo-client-0.2.2.pom'. > Could not GET 'https://jcenter.bintray.com/net/unicon/iam/duo-client/0.2.2/duo-client-0.2.2.pom'. > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Ваша проблема в отсутствующей зависимости библиотеки.Попробуйте добавить compile group: 'net.unicon.iam', name: 'duo-client', version: '0.2.2' к вашему gradle и построить снова.
compile group: 'net.unicon.iam', name: 'duo-client', version: '0.2.2'