I have grails 3.3.9 installed on Mac.

If I create a normal application, e.g. using:

grails create-app myapp

I can create domain classes, views etc, run the app and see the web pages.

However, I need two different web apps (one for the internal backoffice, and one for the customer facing public website). The solution is to create a core plugin which contains only the domain objects and service layer which is then called by the two web apps, and later API apps etc. also.

I followed the official instructions here

i.e.:

$ grails create-plugin core --profile=plugin --features=hibernate5,events
$ Grails create-app myapp
$ create settings.gradle with: include "myapp","core"
$ edit build.grandle of myapp and add:

grails {
    plugins {
        compile project(':core')
    }
}

Now when I try to compile either, or run any grails command (such as grails create-service) I get this:

| Resolving Dependencies. Please wait...
FAILURE: Build failed with an exception.
* Where:
Build file '/Users/me/dev/grails_projects/tst/core/build.gradle' line: 17

* What went wrong:
A problem occurred evaluating project ':core'.
> Failed to apply plugin [id 'org.grails.grails-plugin']
   > Could not find method runtimeOnly() for arguments [io.methvin:directory-watcher] on object of type org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

If I remove the settings.gradle, I can compile the plugin. If I add it back, compile (or any grails command such as create-domain-class) fails with the above error.

Here is the build.gradle:

buildscript {
    repositories {
        mavenLocal()
        maven { url "https://repo.grails.org/grails/core" }
    }
    dependencies {
        classpath "org.grails:grails-gradle-plugin:$grailsVersion"
        classpath "org.grails.plugins:hibernate5:${gormVersion-".RELEASE"}"
    }
}

version "0.1"
group "core"

apply plugin:"eclipse"
apply plugin:"idea"
apply plugin:"org.grails.grails-plugin"
apply plugin:"org.grails.grails-plugin-publish"

The offending line 17 is:

apply plugin:"org.grails.grails-plugin"

I also tried creating the plugin with the name "corex" instead of core just in case that was a reserved word. Got same results - plugin wont compile.

Note, the project directory structure looks like this:

settings.gradle
myapp
   build.gradle
   etc.
core
   build.gradle.
   etc.

I also tried several variations of the line in settings.gradle, including:

1. include 'myapp', 'core'
2. include 'core', 'myapp'
3. include ":myapp", ":core"

Any ideas?

UPDATE 1

I just tried this with 3.3.8 and it seems to work. So it would appear to be a bug in 3.3.9 which prevents using modular apps.