warning: Kotlin runtime JAR files in the classpath should have the same version

Question

I get the following warning, but I'm not sure where v1.0.6 resides.

Is it possible this error comes from a Kotlin library somehow including an old Kotlin version?

Any ideas how to fix it or at least how can I follow the suggestion to make kotlin-reflect explicit (1.1) ?

score 135 · Accepted Answer · edited Nov 21 '19 at 17:01

135

It seems that your project is configured in such a way that you depend on kotlin-stdlib 1.1 and kotlin-reflect 1.0. The most likely case is that you already have an explicit dependency on kotlin-stdlib 1.1 but have no dependency on kotlin-reflect, and some other library (which you depend on) depends on kotlin-reflect 1.0.

If that indeed is the case, the solution is to provide an explicit dependency on kotlin-reflect 1.1.

In Maven, add this to pom.xml:

    <dependencies>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-reflect</artifactId>
            <version>1.1.0</version>
        </dependency>
    </dependencies>

In Gradle, add this to build.gradle:

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-reflect:1.1.0"
}

See some info about this and related warnings in the official docs.

edited Nov 21 '19 at 17:01

jpthesolver2

1,009
1
11
21

answered Mar 03 '17 at 11:12

Alexander Udalov

28,964
6
77
65

What happens when I upgrade to 1.1.1? Will I get warnings again because of this 1.1.0 new dependency? – ycomp Mar 03 '17 at 16:19
6

No, the warning is there only when major/minor versions don't match. We're keeping patch version updates fully compatible between one another – Alexander Udalov Mar 03 '17 at 18:50
3

Where is supposed to be located the `pom.xml` file? – jap1968 Jun 05 '21 at 11:18

jeonghyeon kim · Answer 2 · 2020-04-11T18:55:21.637

firstly, figure out the reason by the gradle script below

./gradlew app:dependencies

(change app to your gradle module name)

+--- project :common
|    +--- org.jetbrains.kotlin:kotlin-stdlib:1.3.61
|    |    +--- org.jetbrains.kotlin:kotlin-stdlib-common:1.3.61
|    |    \--- org.jetbrains:annotations:13.0
|    +--- org.jetbrains.kotlinx:kotlinx-coroutines-core-common:1.3.3
|    |    \--- org.jetbrains.kotlin:kotlin-stdlib-common:1.3.61
|    +--- org.jetbrains.kotlinx:kotlinx-serialization-runtime-common:0.12.0 -> 0.14.0
|    |    \--- org.jetbrains.kotlin:kotlin-stdlib-common:1.3.60 -> 1.3.61

Then, the dependency tree will be shown. check which dependency use the issue dependency.

If you found the dependency, decide how to solve it.

upgrade the dependency's version(the dependency's latest version may refer to latest issue dependency's version)
or exclude the issue dependency from the dependency
or follow other answers.

I'm not sure what is the best way. kindly just refer to it.

This is the best way to troubleshoot hidden dependencies. – mpprdev Feb 16 '22 at 20:03 — mpprdev, Feb 16 '22 at 20:03

score 34 · Answer 3 · answered Oct 31 '18 at 10:47

34

I fixed warning by overwriting kotlin version used in my app

configurations.all {
    resolutionStrategy.eachDependency { DependencyResolveDetails details ->
        def requested = details.requested
        if (requested.group == 'org.jetbrains.kotlin' && requested.name == 'kotlin-reflect') {
            details.useVersion kotlin_version
        }
    }
}

e.g. kotlin_version = 1.3.0

answered Oct 31 '18 at 10:47

Vlad

6,741
2
48
42

1

I added that but still gets the same error. It is driving me nut man... – Joseph Wambura Sep 07 '19 at 07:45
3

@GithithuWambura put it directly in app build.gradle without bracing in `android {}` e.g. – Vlad Sep 07 '19 at 08:18
/*Alternatively*/ configurations.all { resolutionStrategy { eachDependency { if ((requested.group == "org.jetbrains.kotlin") && (!requested.name.startsWith("kotlin-gradle"))) { useVersion(kotlin_version) } } } } – Photon Point Jun 06 '21 at 00:23

score 11 · Answer 4 · answered Oct 20 '19 at 08:28

11

it happens when you are using the dagger in a kotlin project(android) and you have the kotlin version to be 1.7 i.e

implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"

all you have to do is add the dependency below to your app build gradle level

  implementation "org.jetbrains.kotlin:kotlin-reflect:1.3.50"

answered Oct 20 '19 at 08:28

Musa Abdul Wadud

137
1
3

I have tryed this but only changes the error message. No luck. Trying to recompile an old project turns into a nightmare! – jap1968 Jun 05 '21 at 11:15

score 7 · Answer 5 · answered Mar 10 '21 at 05:28

replace this

  implementation 'org.jetbrains.kotlin:kotlin-stdlib:1.4.30'

with

implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.4.30'

the version of library should be same as plugin in project level

 classpath org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.30

score 5 · Answer 6 · answered Oct 01 '20 at 13:13

Make sure you use the same version of stdlib-jdk7 & kotlin-gradle-plugin dependencies to avoid warnings.
You can refere below example where stdlib-jdk7 & kotlin-gradle-plugin both have the same version

app-level build.gradle file

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.4.0"
    ...
}

project-level build.gradle file

buildscript {
    dependencies {
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.0" 
         ...
    }

}

score 2 · Answer 7 · answered Feb 09 '22 at 14:51

2

The Kotlin version in build.gradle and the one bundled with your IDE are of different versions. Check the kotlin version in build.gradle (app) and in Tools -> Kotlin -> Configure Kotlin Plugin Updates.

answered Feb 09 '22 at 14:51

rohegde7

533
6
15

Yup they are different, how to force my project to use a specific version? – lostintranslation Mar 16 '22 at 19:27

Martin Zeitler · Answer 8 · 2022-02-07T10:35:41.693

When this happens for the Lint task, one can list the dependencies with:

./gradlew -q dependencies app:dependencies --configuration lintClassPath

Which shows that eg. kotlin-stdlib-jdk8:1.4.32 is being used:

 +--- org.jetbrains.kotlin:kotlin-reflect:1.4.32 (*)
 \--- org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.4.32 (*)

I've wrote a Gradle script, which equalizes all the Kotlin library versions:

// Runtime JAR files in the classpath should have the same version.
configurations.all {
    resolutionStrategy.eachDependency { DependencyResolveDetails details ->
        def kotlinVersion = "1.6.0"
        def requested = details.requested
        if (requested.group == 'org.jetbrains.kotlin') {
            List<String> list = ['kotlin-stdlib', 'kotlin-stdlib-jdk7', 'kotlin-stdlib-jdk8', 'kotlin-stdlib-common']
            if (list.contains(requested.name)) { details.useVersion kotlinVersion }
        }
    }
}

There is no other way, because some older versions are being pulled in by build tools.
One likely could also add kotlin-reflect into the List<String> list (not tested).

HeartFlutterGuest · Answer 9 · 2022-05-31T13:34:05.510

For flutter initialized project, I commented this line to refer the already available lib

dependencies {
    // implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"

and this was gone:

w: Some runtime JAR files in the classpath have an incompatible version. Consider removing them from the classpath

w: Runtime JAR files in the classpath should have the same version. These files were found in the classpath:

score -8 · Answer 10 · answered Jan 26 '21 at 04:10

-8

FOR ANDROID DEVELOPERS WITH ERROR OCCURING AT XML UNRECOGNIZED FILE

It if it in Android and thew error appears by not recognizing a xml file, you could search for some error in the xml folder files(in my case, one of the files had tag duplicated)

answered Jan 26 '21 at 04:10

Aury0n

163
2
13

This can fit in the comment section not an answer. – Wale Jul 12 '21 at 19:46

warning: Kotlin runtime JAR files in the classpath should have the same version

10 Answers10

Linked