Gradle 6.6.1 and Kotlin 1.4 - runtime version conflict

Question

I use the latest Gradle (v. 6.6.1) and the latest Kotlin (v. 1.4).

buildSrc project defines all Kotlin versions. And unfortunately it receives the error below.

The `kotlin-dsl` plugin applied to project ':buildSrc' enables experimental Kotlin compiler features. For more information see https://docs.gradle.org/6.6.1/userguide/kotlin_dsl.html#sec:kotlin-dsl_plugin
w: Runtime JAR files in the classpath should have the same version. These files were found in the classpath:
    /xxx/.gradle/wrapper/dists/gradle-6.6.1-all/43pddabvuyfjfvs8uyekonb98/gradle-6.6.1/lib/kotlin-stdlib-1.3.72.jar (version 1.3)
    /xxx/.gradle/wrapper/dists/gradle-6.6.1-all/43pddabvuyfjfvs8uyekonb98/gradle-6.6.1/lib/kotlin-stdlib-common-1.3.72.jar (version 1.3)
    /xxx/.gradle/wrapper/dists/gradle-6.6.1-all/43pddabvuyfjfvs8uyekonb98/gradle-6.6.1/lib/kotlin-stdlib-jdk7-1.3.72.jar (version 1.3)
    /xxx/.gradle/wrapper/dists/gradle-6.6.1-all/43pddabvuyfjfvs8uyekonb98/gradle-6.6.1/lib/kotlin-stdlib-jdk8-1.3.72.jar (version 1.3)
    /xxx/.gradle/wrapper/dists/gradle-6.6.1-all/43pddabvuyfjfvs8uyekonb98/gradle-6.6.1/lib/kotlin-reflect-1.3.72.jar (version 1.3)
    /xxx/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-reflect/1.4.0/aa2101a19d8688e368ae6e35e8967550ced73884/kotlin-reflect-1.4.0.jar (version 1.4)
    /xxx/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib-jdk8/1.3.72/916d54b9eb6442b615e6f1488978f551c0674720/kotlin-stdlib-jdk8-1.3.72.jar (version 1.3)
    /xxx/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib-jdk7/1.3.72/3adfc2f4ea4243e01204be8081fe63bde6b12815/kotlin-stdlib-jdk7-1.3.72.jar (version 1.3)
    /xxx/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib/1.4.0/63e75298e93d4ae0b299bb869cf0c627196f8843/kotlin-stdlib-1.4.0.jar (version 1.4)
    /xxx/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib-common/1.4.0/1c752cce0ead8d504ccc88a4fed6471fd83ab0dd/kotlin-stdlib-common-1.4.0.jar (version 1.4)

buildSrc project has the following build.gradle.kts file:

plugins {
    `kotlin-dsl`
}

dependencies {
    api(kotlin("gradle-plugin:1.4.0"))
}

As you can see in the warning above, there are the same libraries in the classpath, however with different versions:

1. With version 1.3 from gradle.
2. With version 1.4 from kotlin plugin.

How can this be fixed?

Answer 1

Had this issue just now; close IntelliJ and running a killall java strangely solved it for me; not sure why.