--- a/rakelib/setup.rake	Wed Jun 27 21:21:19 2018 +0100
+++ b/rakelib/setup.rake	Fri Jul 06 16:35:55 2018 +0100
@@ -20,6 +20,14 @@
 
 unless defined? BUILD_TARGET; BUILD_TARGET = ENV['BUILD_TARGET'] || build_target_guess(); end
 
+# "Guess" the current "branch".
+def build_branch_guess()
+  repo =  HG::Repository.new('.')
+  return repo.bookmark() || repo.branch()
+end
+
+BUILD_BRANCH = build_branch_guess()
+
 unless defined? TOOLCHAIN
   if ENV.has_key? 'TOOLCHAIN'
     TOOLCHAIN = ENV['TOOLCHAIN']