title: groovy.lang.MissingPropertyException: Could not set unknown property 'versionKey' for project ':flamingo' of type org.gradle.api.Project
body: <p>I have this error while trying to compile the flamingo graphic tools for java, using intelliJ.</p>
  
  <p>here is the build.gradle file for the error's project :</p>
  
  <pre><code>import javax.swing.SwingUtilities
  
  dependencies {
    compile project(":trident")
    compile group: 'org.tmatesoft.svnkit', name: 'svnkit', version:'1.2.3.5521'
    compile group:'org.apache.xmlgraphics', name:'batik-swing', version:'1.7'
    compile (group:'org.apache.xmlgraphics', name:'batik-transcoder', version:'1.7') {
      exclude group:'xml-apis'
      exclude group:'xalan'
      exclude group:'commons-io'
      exclude group:'commons-logging'
      exclude group:'org.apache.avalon.framework'
    }
    testCompile group: 'com.jgoodies', name: 'forms', version: '1.2.0'
    testCompile group: 'junit', name: 'junit', version: '4.3.1'
    testCompile group: 'org.easytesting', name: 'fest-assert', version: '1.2'
    testCompile group: 'org.easytesting', name: 'fest-reflect', version: '1.2'
    testCompile group: 'org.easytesting', name: 'fest-swing', version: '1.2.1'
    testCompile group: 'org.easytesting', name: 'fest-swing-junit', version: '1.2.1'
    testCompile group: 'org.easytesting', name: 'fest-swing-junit-4.3.1', version: '1.2.1'
  }
  
  sourceSets {
    main
    test
  }
  
  test {
    // if we are headless, don't run our tests
    enabled = !Boolean.getBoolean("java.awt.headless")
  }
  
  jar {
    manifest {
      attributes(
          "Flamingo-Version": version,
          "Flamingo-VersionName": versionKey,
      )
    }
  }
  
  task testJar(type: Jar) {
    classifier = 'tst'
  
    from sourceSets.test.classes
  
    manifest {
      attributes(
          "Flamingo-Version": version,
          "Flamingo-VersionName": versionKey,
      )
    }
  }
  
  uploadArchives {
    try {
      def x = [deployUsername, deployPassword]
    } catch (Exception e) {
      deployUsername = 'unset'
      deployPassword = ''
    }
    repositories {
      mavenDeployer {
        snapshotRepository(url: "https://oss.sonatype.org/content/repositories/snapshots/") {
          authentication userName: deployUsername, password: deployPassword
        }
        repository(url: "https://oss.sonatype.org/service/local/staging/deploy/maven2/") {
          authentication userName: deployUsername, password: deployPassword
        }
        configurePOM(pom)
      }
    }
  }
  
  install {
    configurePOM(repositories.mavenInstaller.pom)
  }
  
  private def configurePOM(def pom) {
    configureBasePom(pom)
    pom.project {
      name "flamingo"
      description "A fork of @kirilcool's flamingo project"
      url "http://insubstantial.github.com/peacock"
    }
    // deal with a gradle bug where transitive=false is not passed into the generated POM
    pom.whenConfigured {cpom -&gt;
      cpom.dependencies.each {it
        switch (it.artifactId) {
          case 'trident':
            it.classifier = 'swing'
            break
        }
      }
    }
  }
  </code></pre>
  
  <p>I don't know what to add for the version key, nor where.</p>
  
  <p>The project is on GitHub : <a href="https://github.com/erichschroeter/insubstantial" rel="nofollow noreferrer">it's a fork of the original project flamingo</a>.</p>
  
  <p>Here is the build.gradle file inside the root directory:</p>
  
  <pre><code>buildscript {
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath 'de.huxhorn.gradle:de.huxhorn.gradle.pgp-plugin:0.0.3'
      }
  }
  
  subprojects {
    apply plugin: 'java'
    apply plugin: 'maven'
    try {
      def test = pgpSecretKeyRingFile // exception will throw if not set
      apply plugin: 'sign'
      apply plugin: de.huxhorn.gradle.pgp.PgpPlugin
    } catch (Exception ignore) {}
  
    group = 'com.github.insubstantial'
    version = '6.3-SNAPSHOT'
    versionKey = "6.3-defender"
    release = "internal"
  
    sourceCompatibility = 1.6
    targetCompatibility = 1.6
  
    configurations {
      maven { extendsFrom archives }
    }
  
    repositories {
      mavenRepo urls: 'https://oss.sonatype.org/content/groups/staging'
      mavenCentral()
      mavenRepo urls: new File(System.getProperty('user.home'), '.m2/repository').toURI().toString()
    }
  
    task sourceJar(type: Jar) {
      from sourceSets.main.java
      from sourceSets.main.resources
      classifier = 'sources'
    }
  
    task javadocJar(type: Jar) {
      dependsOn javadoc
      from javadoc.destinationDir
      classifier = 'javadoc'
    }
  
    artifacts {
      maven sourceJar
      maven javadocJar
    }
  
    uploadArchives {
      try {
        def x = [deployUsername, deployPassword]
      } catch (Exception e) {
        deployUsername = 'unset'
        deployPassword = ''
      }
      configuration = configurations.maven
      repositories {
        mavenDeployer {
          snapshotRepository(url: "https://oss.sonatype.org/content/repositories/snapshots/") {
            authentication userName: deployUsername, password: deployPassword
          }
          repository(url: "https://oss.sonatype.org/service/local/staging/deploy/maven2/") {
            authentication userName: deployUsername, password: deployPassword
          }
        }
      }
    }
  
    install {
      configuration = configurations.maven
    }
  
    configureBasePom = { pom -&gt;
      pom.project {
        modelVersion '4.0.0'
        packaging 'jar'
        scm {
          connection 'scm:git:git@github.com:Insubstantial/insubstantial.git'
          developerConnection 'scm:git:git@github.com:Insubstantial/insubstantial.git'
          url 'scm:git:git@github.com:Insubstantial/insubstantial.git'
        }
        developers {
          developer {
            name 'Kirill Grouchnikov'
            email 'kirillcool@yahoo.com'
            roles {
              role 'author'
              role 'developer'
            }
          }
          developer {
            name 'Danno Ferrin'
            email 'danno.ferrin@shemnon.com'
            roles {
              role 'maintainer'
            }
          }
        }
      }
    }
  }
  
  task wrapper(type: Wrapper) {
    gradleVersion = '1.0-milestone-2'
  }
  </code></pre>
  
  <p>moreover, the main build.gradle contains the word "Exception" which raise an error from intelliJ.</p>