grails - Implicit dependency to json-lib-2.4-jdk15.jar causes build to fail, even though it's been excluded in build.gradle -

i'm converting existing maven based project containing grails 2.4.2 application gradle 2.6 , grails 3.0.4. it's mixed environment java, groovy, , grails used in several sub-projects. i've converted pom.xml files build.gradle files, starting off ./gradlew init, , hand editing needed. before converting grails project's grails-app/conf/buildconfig.groovy build.gradle equivalent, built fine gradle 2.6. after converted grails project's buildconfig.groovy file build.gradle, i'm getting following error when trying run ./gradlew build:

failure: build failed exception.  * went wrong: not resolve dependencies configuration ':foo:runtime'. > not find json-lib-jdk15.jar (net.sf.json-lib:json-lib:2.4). searched in following locations:   file:/users/xyz/.m2/repository/net/sf/json-lib/json-lib/2.4/json-lib-2.4-jdk15.jar  * try: run --stacktrace option stack trace. run --info or --debug option more log output.  build failed 

the json-lib-2.4.jar file exist in local m2 cache shown above, doesn't have -jdk15 part in it. there's no explicit dependency json-lib jar file in build.gradle file grails project. parallel project have explicit dependency on library, project builds fine. i've tried explicitly add dependency build.gradle file in grails project both , without "classifier: 'jdk15'" dependency declaration. when ran ./gradlew dependencies, noticed older version (2.3) of json-lib jar file showed in list implied dependency apache httpcomponent stuff. tried both versions of in allprojects section of top level build.gradle:

configurations {     all*.exclude module: 'json-lib' } 

as as:

configurations {     all*.exclude module: 'json-lib', classifier: 'jdk15' } 

neither variant makes difference. i'm stuck on , appreciate tips on how move forward. in case makes difference, i'm running on mac macos 10.10.5, jdk version 1.8.0_25-b17. thanks.

dependencies {     //compile group: 'net.sf.json-lib', name: 'json-lib', version: '2.4'     compile "net.sf.json-lib:json-lib:2.4:jdk15" }