How can I use extraDirectories property correctly in a build.gradle.kts

Environment:

• Jib version: 2.5.0
• Build tool: Gradle 6.5.1 (Kotlin 1.3.72, Groovy 2.5.11, Ant 1.10.7, JVM 11.0.8)
• OS: Ubuntu 20.04.1 LTS

Description of the issue: I tried to use the extraDirectories.paths.path to bundle my native shared libraries, but It always said Val cannot be reassigned. How can I fix it?

Steps to reproduce:

1. Generate a simple gradle project using gradle init --type java-application.
2. Add a jib configuration in build.gradle.kts.
3. Run ./gradlew jibDockerBuild

jib-gradle-plugin Configuration:

A short part of my build.gradle.kts.

    
jib {
    from.image = "openjdk:14"
    to.image = "simple_test"
    to.tags = setOf("$version")
    container {
        mainClass = "some.simple.project.App"
        jvmFlags = listOf("-Djava.library.path=${jib.container.appRoot}/native-libs")
        creationTime = "USE_CURRENT_TIMESTAMP"
    }
    extraDirectories {
        //paths.add(ExtraDirectoryParameters("native-libs/linux-amd64", "${jib.container.appRoot}/native-libs"))
        paths {
            path {
                from = "native-libs/linux-amd64"
                into = "${jib.container.appRoot}/native-libs"   
            }
        }
    }
}

Log output:

✦ ❯ ./gradlew jibDockerBuild 

> Configure project :
e: /home/xx/Projects/XX/build.gradle.kts:109:17: Val cannot be reassigned
e: /home/xx/Projects/XX/build.gradle.kts:109:24: Type mismatch: inferred type is String but Path! was expected

FAILURE: Build failed with an exception.

* Where:
Build file '/home/xx/Projects/XX/build.gradle.kts' line: 109

* What went wrong:
Script compilation errors:

  Line 109:                 from = "native-libs/linux-amd64"
                            ^ Val cannot be reassigned

  Line 109:                 from = "native-libs/linux-amd64"
                                   ^ Type mismatch: inferred type is String but Path! was expected

2 errors

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/6.5.1/userguide/command_line_interface.html#sec:command_line_warnings

BUILD FAILED in 909ms

Additional Information: I use Gradle kotlin DSL now.

[chanseokoh]

@hwiorn thanks for the report. Looks like this is something we overlooked, as we don’t have a lot of experience with Kotlin. Can’t really understand the exact reason why Kotlin doesn’t allow this, but for now, you can explicitly call ExtraDirectoryParameters.setFrom(Object), which I confirmed works.

    extraDirectories {
        paths {
            path {
                setFrom("native-libs/linux-amd64")
                into = "${jib.container.appRoot}/native-libs"   
            }
        }
    }

[chanseokoh]

Glad it worked. We will keep this open to track the issue with Kotlin.