Gradle copy local jar into cache - gradle

Question

I need some help understanding why my build.gradle does not copy locally referred jar into its cache. On Windows, I expected to see jars in C:\Users\myusername .gradle and indeed other JARs are there.
I can't import this JAR in IntelliJ as it does not find it.
Side question: did anybody figure out how to debug Gradle's DSL? I set up remote debugging and IntelliJ never hits my breakpoint. It does not the have the checkbox on it so I guess IDE does not think it is code.
Few things are not making sense to me:
1. gradle dependencies --configuration compile
\--- com.google.guava:guava:23.5-jre
+--- com.google.code.findbugs:jsr305:1.3.9
....
MY_JAR_1.0.1.jar is not present.
2. gradle copyDependencies - this task finds and copies it.
task copyDependencies(type: Copy) {
from configurations.compile
into 'dependencies'
}
3. This task also finds my jar.
task listcompile << {
configurations.compile.each { File file -> println file.name }
}
Why does #1 not find it?
apply plugin: 'java'
repositories {
mavenCentral()
//flatDir {
// dirs 'customlibs'
//}
}
dependencies {
compile group: 'com.google.guava', name: 'guava', version: '23.5-jre'
compile files('customlibs/MY_JAR_1.0.1.jar')
}
task listcompile << {
configurations.compile.each { File file -> println file.name }
}
// copy all dependencies into this folder
task copyDependencies(type: Copy) {
from configurations.compile
into 'dependencies'
}

Answer 1

It seems that Gradle's dependencies task will only display modules that have a defined group:name:version coordinate. You are adding a file directly, with no associated identifier.
What you can do instead is add a flat directory repository and declare your custom JAR as a normal dependency, like so:
repositories {
flatDir {
dirs 'customlibs'
}
}
dependencies {
compile ':MY_JAR:1.0.1'
}
You will need to rename the JAR so that it matches the naming convention for Maven/Gradle, i.e. MY_NAME-1.0.1.jar (replacing the last underscore with a hyphen).