Handle scenario where branch name contains double hyphen

src/integTest/groovy/nebula/plugin/release/ReleasePluginIntegrationSpec.groovy

@@ -67,6 +67,16 @@ class ReleasePluginIntegrationSpec extends GitVersioningIntegrationTestKitSpec {
         version == dev('0.1.0-dev.2+testexample.')
     }
 
+    def 'build on non standard branch with double hyphen fails with right context'() {
+        git.checkout(branch: 'test--example', createBranch: true)
+
+        when:
+        def result = runTasksAndFail('devSnapshot')
+
+        then:
+        result.output.contains("Branch test--example is invalid. Nebula Release plugin does not support branches that contain double dash (-) as it leads to bad build metadata for SemVer")
+    }
+
     def 'choose devSnapshot version'() {
         when:
         def version = inferredVersionForTask('devSnapshot')

src/main/groovy/nebula/plugin/release/ReleasePlugin.groovy

@@ -395,7 +395,12 @@ class ReleasePlugin implements Plugin<Project> {
             return
         }
         if (currentBranch.endsWith('-')) {
-            throw new GradleException('Nebula Release plugin does not support branches that end with dash (-)')
+            throw new GradleException('Nebula Release plugin does not support branches that end with dash (-).' +
+                    'Please rename your branch')
+        }
+        if (currentBranch.contains('--')) {
+            throw new GradleException("Branch ${currentBranch} is invalid. Nebula Release plugin does not support branches that contain double dash (-) as it leads to bad build metadata for SemVer." +
+                    " Please rename your branch")
         }
         if (currentBranch ==~ /release\/\d+(\.\d+)?/) {
             throw new GradleException('Branches with pattern release/<version> are used to calculate versions. The version must be of form: <major>.x, <major>.<minor>.x, or <major>.<minor>.<patch>')