Use the git-version plugin.

build.gradle

-import org.eclipse.jgit.api.Git
-import org.eclipse.jgit.storage.file.FileRepositoryBuilder
-
 subprojects {
-    def gitdir = new File(projectDir.parent, '.git')
-    if (gitdir.isFile()) {
-        gitdir = new File(projectDir.parent, gitdir.text.replace('gitdir: ','').trim())
-    }
-
-    def repo = new FileRepositoryBuilder().setGitDir(gitdir).build()
-    def git = Git.wrap(repo)
-    def objectId = git.log().addPath(projectDir.name).setMaxCount(1).call().first().id
-    project.version = git.describe().setTarget(objectId).call() + '-SNAPSHOT'
-
+    apply plugin: 'com.dmdirc.git-version'
     apply plugin: 'java'
     apply plugin: 'findbugs'
     apply plugin: 'pmd'
 buildscript {
     repositories {
         mavenCentral()
-        maven {
-            url 'http://artifactory.dmdirc.com/artifactory/repo'
-        }
+        maven { url 'http://artifactory.dmdirc.com/artifactory/repo' }
+        maven { url 'https://dl.bintray.com/dmdirc/releases/' }
     }
 
     dependencies {
-        classpath group: 'org.eclipse.jgit', name: 'org.eclipse.jgit', version: '3.6.1.201501031845-r'
+        classpath group: 'com.dmdirc', name: 'git-version', version: '1.0'
     }
 }