Gradle Cannot Add Properties Via Command-Line

So, I am a bit new to Gradle. I have a build file that I have been trying to debug for hours now. I am executing it through eclipse’s Run Configurations to pass in command-line parameters. This is it:

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'application'

repositories {
    maven {
        url ""
    flatDir {
       dirs 'libs'

sourceCompatibility = 1.8
version = "1.0.0-SNAPSHOT"

dependencies {
	runtime fileTree("../BidirectionalDetector/build/libs")
	compile name: 'soot-3.0.0-jar-with-dependencies'
	compile name: 'plantuml-6703'
	compile name: 'SignatureEvaluator-1.0.9'
	compile 'org.apache.logging.log4j:log4j-api:2.+'
	compile 'org.apache.logging.log4j:log4j-core:2.+'
    testCompile 'junit:junit:4.+'
    testCompile "org.mockito:mockito-core:2.+"

compileJava {
    options.compilerArgs << '-g'

mainClassName = "csse374.infamousyams.main.Main"
applicationDefaultJvmArgs = ["-Xms512m", "-Xmx1024m"]
run {
	standardInput =
	println "has property: " + project.hasProperty("args")
	println "has property: " + project.hasProperty("appArgs")

	if ( project.hasProperty("appArgs") ) {
		String passed = project.getProperty("appArgs");
		List<String> toReturn = new ArrayList<>();
		java.util.regex.Pattern p = java.util.regex.Pattern.compile("(?:([^\\s^\"]+)|(\"[^\"]*\"))");
		java.util.regex.Matcher m = p.matcher(passed);
		while(m.find()) {
		args toReturn.toArray()
		println args

task myRun(type: JavaExec, dependsOn: run) {
	doLast {
		println args
		println "has property: " + project.hasProperty("args")

jar {
    manifest {
        attributes 'Implementation-Title': '374UMLDesigner',
                   'Implementation-Version': '${version}'

task wrapper(type: Wrapper) {
	gradleVersion = '4.3.1'

I am trying to add properties from the command-line using -Pappprop=“some string for a property”.
I tried multiple solutions online, but none seem to work. Am I doing something wrong?

This is the output I get:

has property: false
has property: false

FAILURE: Build failed with an exception.

* What went wrong:
Problem configuring task :build from command line.
> Unknown command-line option '-P'.

These are the run configs I ran:

build -PappArgs=[....]


What am I doing that is causing this to happen?


Where are you adding the command line arguments? The error mentioned can occur if you try to provide your arguments in the tasks field instead of specifically in the arguments section of the configuration.