gradlew build won't compile on debian 9.

[bobifle]

• Where:
  Build file '/home/bob/nerps/MapTool/build.gradle' line: 52
  A problem occurred evaluating root project 'MapTool'.

No signature of method: org.eclipse.jgit.internal.storage.file.FileRepository.getRef() is applicable for argument types: (java.lang.String) values: [HEAD]
Possible solutions: getAt(java.lang.String), getFS(), grep(), exactRef(java.lang.String), findRef(java.lang.String), getAllRefs()

The following modification allows me to successfully build/run maptool

diff --git a/build.gradle b/build.gradle
index 822e0ad..051c566 100644
--- a/build.gradle
+++ b/build.gradle
@@ -49,7 +49,7 @@ ext {
        git = org.ajoberstar.grgit.Grgit.open(currentDir: file('.'))
        revision = git.head().abbreviatedId
        revisionFull = git.head().id
-       branch = git.branch.getCurrent().getName()
+       branch = "master"
        gdxVersion = '1.9.6'
        box2DLightsVersion = '1.4'
        //aiVersion = '1.8.0'

[JamzTheMan]

I already have this fixed in 1.4.5.0.