[Help] sample unitTest.xml when build in salesforce

[ilentt]

I create build.gradle at root project folder with content such as:
//////////
buildscript {
repositories {
mavenCentral()
jcenter()
}
dependencies {
classpath 'org.fundacionjala.gradle.plugins.enforce:enforce-gradle-plugin:1.1.2'
}
}

apply plugin: 'enforce'

enforce {
srcPath = 'src'
}
$ gradle CI-Demo -PcredentialId=68418bd0-6cc1-42c3-a331-0f8955f48050
$ gradle runTest

//////////

after build finish I receive failed message such as:

//////////
[htmlpublisher] Archiving HTML reports...
[htmlpublisher] Archiving at BUILD level /opt/bitnami/apps/jenkins/jenkins_home/workspace/CI-Demo/build/report to /opt/bitnami/apps/jenkins/jenkins_home/jobs/CI-Demo/builds/35/htmlreports/Code_Coverage
Recording test results
ERROR: Step ‘Publish JUnit test result report’ failed: Test reports were found but none of them are new. Did tests run?
For example, /opt/bitnami/apps/jenkins/jenkins_home/workspace/CI-Demo/build/report/unitTest.xml is 46 min old

Sending e-mails to: [email protected]
Finished: FAILURE
//////////

Please show me how to setup unitTest.xml to pass this failed

Thank you.