A short note ahead: Kotlin requires at least Java 6. You might want to correct your sourceCompatibility.
Here’s the output that I get when I run your build.gradle:
22:01 $ ./gradlew build
:compileKotlin
Download https://jitpack.io/com/github/jkcclemens/khttp/d4c7950154/khttp-d4c7950154.pom
Download https://repo1.maven.org/maven2/org/json/json/20150729/json-20150729.pom
Download https://jitpack.io/com/github/jkcclemens/khttp/d4c7950154/khttp-d4c7950154.jar
Download https://repo1.maven.org/maven2/org/json/json/20150729/json-20150729.jar
No Kotlin files found, skipping Kotlin compiler task
:compileJava
warning: [options] bootstrap class path not set in conjunction with -source 1.5
warning: [options] source value 1.5 is obsolete and will be removed in a future release
warning: [options] target value 1.5 is obsolete and will be removed in a future release
warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.
4 warnings
:processResources UP-TO-DATE
:classes
:jar
:assemble
:compileTestKotlin
No Kotlin files found, skipping Kotlin compiler task
:compileTestJava
warning: [options] bootstrap class path not set in conjunction with -source 1.5
warning: [options] source value 1.5 is obsolete and will be removed in a future release
warning: [options] target value 1.5 is obsolete and will be removed in a future release
warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.
4 warnings
:processTestResources UP-TO-DATE
:testClasses
:test
:check
:build
BUILD SUCCESSFUL
Total time: 15.133 secs
Please post the full error message because it can’t be reproduced with what you show us in your initial posting. May I kindly ask that you also improve the formatting to improve readability. Thank you!
Finally I’m using Fuel library https://github.com/kittinunf/Fuel instead of Khttp and it works… I think it wasn’t build.grandle fault. Maybe Khttp is not updated.