Send mails on package build failures

For now send them to myself only. Once this works we can switch to a
list.

jobs.groovy

@@ -36,6 +36,9 @@ def native_archs = [ primary_arch, 'amd64' ]
 // Artifacts
 def artifacts = '*.deb'
 
+// Who get's mail notifications
+def email_to = 'guido.gunther@puri.sm'
+
 // Load jobs from YAML file
 Yaml yaml = new Yaml()
 def jobsfile = (new File(__FILE__)).parent + '/jobs.yml'
@@ -98,35 +101,45 @@ pkgs.each { pkg ->
                 properties properties: [
                     disableConcurrentBuilds()
                 ]
-                stage('Build Debian Package') {
-                  node ('${build_node_label}') {
-                    checkout([
-                      userRemoteConfigs: [[url: '${params.url}']],
-                                          \$class: 'GitSCM',
-                                          branches: [[name: '${branch}']],
-                                          extensions: [[\$class: 'RelativeTargetDirectory',
-                                          relativeTargetDir: 'build'],
-                                         ],
-                      ])
-                    sh '''${build_cmd}'''
-                    stash name: '${stash}', allowEmpty: false, includes: "${uploads.replaceAll(' ',',')}"
+                try {
+                  stage('Build Debian Package') {
+                    node ('${build_node_label}') {
+                      checkout([
+                        userRemoteConfigs: [[url: '${params.url}']],
+                                            \$class: 'GitSCM',
+                                            branches: [[name: '${branch}']],
+                                            extensions: [[\$class: 'RelativeTargetDirectory',
+                                            relativeTargetDir: 'build'],
+                                           ],
+                        ])
+                      sh '''${build_cmd}'''
+                      stash name: '${stash}', allowEmpty: false, includes: "${uploads.replaceAll(' ',',')}"
+                    }
                   }
-                }
 
-                stage('Upload Debian Packages') {
-                  node ('${upload_node_label}') {
-                    sh 'rm -f ${uploads}'
-                    unstash '${stash}'
-                    sh '''${upload_cmd}'''
+                  stage('Upload Debian Packages') {
+                    node ('${upload_node_label}') {
+                      sh 'rm -f ${uploads}'
+                      unstash '${stash}'
+                      sh '''${upload_cmd}'''
+                    }
                   }
-                }
 
-                stage('Save Artifacts') {
-                  node ('${upload_node_label}') {
-                    archiveArtifacts '${artifacts}'
+                  stage('Save Artifacts') {
+                    node ('${upload_node_label}') {
+                      archiveArtifacts '${artifacts}'
+                    }
                   }
+                } catch(err) {
+                  currentBuild.result = 'FAILURE'
+                  emailext body: '\${DEFAULT_CONTENT}',
+                           replyTo: '\$DEFAULT_REPLYTO',
+                           subject: '\${DEFAULT_SUBJECT}',
+                           to: '${email_to}'
+                  // Rethrow error
+                  throw err
                 }
-            }
+              }
             """.stripIndent())
           }
         }