updateCompatibleVersions.sbt

lazy val updateCompatibleVersions = { st: State =>
  val extracted = Project.extract(st)
  val releaseVersion = extracted.get(version)
  val vcs = extracted.get(ReleasePlugin.autoImport.releaseVcs).get
  val vcsBase = vcs.baseDir.getCanonicalFile
  val sign = extracted.get(ReleasePlugin.autoImport.releaseVcsSign)
  val file = extracted.get(zen.compatibleVersionsFile)
  val vcsFile = IO.relativize(vcsBase, file).get

  val compVersions = s"""zen.compatibleVersions in ThisBuild := Set("$releaseVersion")"""

  IO.writeLines(file, Seq(compVersions))

  vcs.add(vcsFile) !
  val status = (vcs.status !!).trim
  if (status.nonEmpty) {
    vcs.commit("Updating compatible versions", sign) !
  }
  st
}