Could not add file 'xxx-dist.tar' to TAR 'xxx-dist.tar' in Jenkins

I have written a web app project (say frs) in java. it consists of frs-core and frs-ui modules. core is built by gradle and ui is built by node v9.5.0 tools. after that maven unifies both modules and convert into TAR format. but when it finally wants to join them together, below error aroused:

The build folder is ready to be deployed. You may serve it with a static server:

  yarn global add serve   serve -s build

Find out more about deployment here:

  http://bitttttttt

:frs-ui:distTar FAILED

FAILURE: Build failed with an exception.

* What went wrong: Execution failed for task ':frs-ui:distTar'.
> Could not add file '/home/samat/workspace/ttbank_frs-2.Build/frs-ui/build/distributions/frs-ui-1.0.0-9dcad410730dbec6f401254f464582e2fa8cd838-build.tar' to TAR '/home/samat/workspace/ttbank_frs-2.Build/frs-ui/build/distributions/frs-ui-1.0.0-9dcad410730dbec6f401254f464582e2fa8cd838-build.tar'.

and here is my build.gradle configuration

>     group = 'ir.samatco.frs'
>     version = '1.0.0'
> 
>     apply from: "$rootDir/gradle/ci.gradle" }
> 
> ext {
>     javaProjects = [':frs-core', ':frs-gateway'].collect { project it }
>     webProjects = [':frs-ui'].collect { project it } }
> 
> subprojects {
>     if (project in javaProjects) {
>         apply plugin: 'java'
>         sourceCompatibility = 1.7
>         targetCompatibility = 1.7
>         [compileJava, compileTestJava]*.options*.encoding = 'UTF-8'
>     }
> 
>     if (project in webProjects) {
>         task npmBuild(type: Exec) {
>             workingDir projectDir
>             executable 'npm'
>             args 'run', 'build'
>         }
>         task distTar(type: Tar) {
>             dependsOn npmBuild
>             baseName = "${project.name}-${project.version}"
>             compression 'gzip'
>             extension 'tar'
>             destinationDir = "$buildDir/distributions" as File
>             from('dist') { into('/') }
>         }
>         idea {
>             module { //                excludeDirs = [".tmp", "bower_components", "dist", "node_modules"].collect {
> file("$projectDir/$it") }
>                 excludeDirs = ["dist", "node_modules"].collect { file("$projectDir/$it") }
>                 sourceDirs = [file("$projectDir/src")]
>             }
>         }
>     }
> 
>     apply plugin: 'maven-publish'
> 
>     publishing {
>         publications {
>             maven(MavenPublication) {
>                 artifact distTar {
>                     classifier 'dist'
>                 }
>             }
>         }
>         repositories {
>             maven() {
>                 credentials {
>                     username project.nexus_user
>                     password project.nexus_pass
>                 }
>                 url "http://nexus.devsamat.ir/content/repositories/test/"
>             }
>         }
>     } }
> 
> task stage {
>     dependsOn subprojects*.publish }

what's the matter that arouses "could not add file...to TAR ..." thanks a milion.