// rest of your build
// Verfied with gradle 4.10
task("checkEnv"){
    doFirst {
        def listOfFileToCheckInPath = ['find', 'grep']
        listOfFileToCheckInPath.each { file ->
            if(!isFoundInPath(file))
                throw new GradleException("${file} was not found in any of the folder in PATH: ${System.getenv('PATH').split(File.pathSeparator)}")
        }
    }
}
/**
 * Static function to verify if a file/command exist in PATH environment
 * @param file
 * @return true if found, else false
 */
def static isFoundInPath( file){
    def PATH_ENV = System.getenv('PATH')
    def fileFound = PATH_ENV.split(File.pathSeparator).find{ folder ->
        println("Looking for ${file} in ${folder}")
        if (Paths.get( "${folder}${File.separator}${file}").toFile().exists()){
            println("Found ${file} in ${folder}")
            return true
        }
    }
    return fileFound
}
// Making test task to depend on checkEnv
test.dependsOn checkEnv