IDEA showing a project twice in tree - intellij-idea

Question

I have a Kotlin project with Gradle that has two children. Whenever I try to open it in IDEA, one of the children is shown twice in the tree.
In the tree, you can see two projects at top level, grpc and grp. The issue is that grpc (from top level) is the same project as the grpc that's a children of grp.
Here are my Gradle build files:
The parent gradle.build:
buildscript {
ext.kotlin_version = '1.0.1'
repositories {
jcenter()
mavenCentral()
}
dependencies {
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
}
}
allprojects {
repositories {
jcenter()
mavenCentral()
}
}
The gradle.settings file:
include ':grpstd', ':grpc'
The grpc gradle.build:
apply plugin: 'antlr'
apply plugin: 'application'
apply plugin: 'kotlin'
mainClassName = 'sron.grpc.MainKt'
compileKotlin.dependsOn generateGrammarSource
generateGrammarSource {
arguments += ['-package', 'sron.grpc.compiler.internal']
}
dependencies {
antlr 'org.antlr:antlr4:4.5.2-1'
compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
compile 'commons-cli:commons-cli:1.3.1'
compile 'org.ow2.asm:asm:5.0.4'
compile project(':grpstd')
testCompile 'junit:junit:4.12'
testCompile "org.jetbrains.kotlin:kotlin-test:$kotlin_version"
}
The grpstd gradle.build:
apply plugin: 'kotlin'
dependencies {
compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
testCompile 'junit:junit:4.12'
testCompile "org.jetbrains.kotlin:kotlin-test:$kotlin_version"
}
Why is that project being shown twice? How can I prevent it?

Answer 1

Open your project structure dialog (you can use Ctrl+Alt+Shift+S), turn to the Modules section, check if you have duplicated module defined there.
If there is, remove the unnecessary ones.

Answer 2

You may want to try disabling the Create separate module per source set option when importing the Gradle module.
So, the full steps are:
Open Modules
Remove the gradle module
Re-import the module. On the second page of the import wizard make sure you disable the option: Create separate module per source set