+
+@node Building GUB
+@section Building GUB
+
+GUB - the Grand Unified Builder - is used to build the release
+versions of LilyPond. For background information, see
+@ref{Grand Unified Builder (GUB)}. The simplest way to set up a
+GUB build environment is to use a virtual machine with LilyDev
+(@ref{LilyDev}). Follow the instructions on that page to set this
+up. Make sure that your virtual machine has enough disk space -
+a GUB installation takes over 30 GBytes of disk space, and if you
+allocate too little, it will fail during the setting up stage and
+you will have to start again. 64 GBytes should be sufficient.
+
+While GUB is being built, any interruptions are likely to make it
+almost impossible to restart. If at all possible, leave the build
+to continue uniterrupted.
+
+Download GUB and start the set up:
+
+@example
+git clone git://github.com/gperciva/gub/gub.git
+cd gub
+make bootstrap
+@end example
+
+This downloads and installs a number of packages. You may find
+some fail during download and you will need to download them
+manually. For example, the perl archive. If this happens,
+download it from
+@uref{http://www.cpan.org/src/5.0/perl-5.10.0.tar.gz}, saving the
+archive to @file{gub/downloads/perl/}. Continue the set up with:
+
+@example
+make bootstrap
+@end example
+
+Once this has completed successfully, you can build the LilyPond
+release package. However, this uses an archived version of the
+regression tests, so it is better to download this first.
+Download the test output from lilypond.org:
+
+@smallexample
+@uref{http://lilypond.org/download/binaries/test-output/lilypond-2.15.33-1.test-output.tar.bz2}
+@end smallexample
+
+Copy the tarball into @file{gub/regtests/}, and tell the build
+system that you have done this:
+
+@example
+touch regtests/ignore
+@end example
+
+Now start the GUB build:
+
+@example
+make lilypond
+@end example
+
+That's it. This will build LilyPond from current master. To build
+the current unstable release, run:
+
+@example
+make LILYPOND_BRANCH=release/unstable lilypond
+@end example