Seems to be occurring since the app server updated to 8.1.0.Final-SNAPSHOT. It could be an issue with the grep/sed for the app server version.

Building AS
First time checkout of AS7
Cloning into jboss-as...
From https://github.com/wildfly/wildfly

• [new branch] 7.1 -> upstream/7.1
• [new branch] 7.1-ignore -> upstream/7.1-ignore
• [new branch] master -> upstream/master
• [new branch] master-ignore -> upstream/master-ignore
• [new tag] 7.1.2-prerelease -> 7.1.2-prerelease
• [new tag] 7.1.2.Final -> 7.1.2.Final
• [new tag] 7.1.3.Beta1 -> 7.1.3.Beta1
• [new tag] 7.2.0.Final -> 7.2.0.Final
• [new tag] 7.2.0.Final-prerelease1 -> 7.2.0.Final-prerelease1
• [new tag] 8.0.0.Alpha1 -> 8.0.0.Alpha1
• [new tag] 8.0.0.Alpha2 -> 8.0.0.Alpha2
• [new tag] 8.0.0.Alpha3 -> 8.0.0.Alpha3
• [new tag] 8.0.0.Alpha4 -> 8.0.0.Alpha4
• [new tag] 8.0.0.Beta1 -> 8.0.0.Beta1
• [new tag] 8.0.0.CR1 -> 8.0.0.CR1
• [new tag] 8.0.0.Final -> 8.0.0.Final
• [new tag] 8.1.0.CR1 -> 8.1.0.CR1
  This is the JBoss-AS commit
  4e5271d07ace06e19745b933f9141f718bdce1b5
  From https://github.com/wildfly/wildfly
• branch master -> FETCH_HEAD
  Current branch 5_BRANCH is up to date.
  AS version is <version>8.1.0.Final-SNAPSHOT</version>
  Need to upgrade the jboss-as.version in the narayana pom.xml to
  Build step 'Execute shell' marked build as failure
  Archiving artifacts
  Sending e-mails to: *****
  Finished: FAILURE