Options supported by GEANT 3.21's debian/rules in $DEB_BUILD_OPTIONS:

 noopt:     Compile everything with no optimization, i.e. -O0.  The default
            is to compile at -O2 or -O3 for almost all files.
 nostrip:   Do not strip debugging information from the binaries and libraries.
 ifort:     Compile with Intel's icc and ifort (formerly ifc) compilers, not
            gcc/gfortran.  You must first set and export $LD_LIBRARY_PATH, or
	    edit /etc/ld.so.conf and run ldconfig, such that the Intel library
	    libimf.so is in the library runtime search path.  This option has
	    not been fully tested.

Targets supported by GEANT 3.21's debian/rules:

 help:              Output this text (found in debian/README.source).
 get-orig-source:   Download upstream sourcecode in tar.gz form to a subdir
                    "upstream" of the current dir.  Requires wget.
 remove-deadpool:   Delete files with licensing issues from upstream tarballs.
 orig.tar.gz:       Build a new orig.tar.gz file in the dir ".."  Don't do this
                    if you already have one; the tarball md5sum will change!
		    This target automatically executes the previous one first.
 unpack:            Expand the upstream tarballs into a subdir "src" of the
                    current dir.
 patched, patch:    (These are synonyms.) Apply Debian patches to the unpacked
                    source code.  After this target has been called, any
		    additional edits to the source code will be preserved when
		    running "fakeroot debian/rules binary".
 unpatch:           De-apply Debian patches without deleting unpacked source.
 build, clean, etc: Standard Policy-required targets.

It may be of interest to describe some of the contents of the debian directory:

 add-ons:	Non Debian-specific additions to GEANT 3.21, including such
		things as man pages, X11 application defaults, and
		a master Makefile.

 control.d:	Fragments of the debian/control file.  It is regenerated from
 		these snippets by "debian/rules clean".

 debhelper:	Files for debhelper tools, kept here so things are tidier.
 		These are symlinked from the main debian directory at build
		time by "debian/rules install-common", and the symlinks are
		removed by "debian/rules clean".

 lintian:	Lintian overrides.

 patches:	Debian patches to GEANT 3.21 source in dpatch format.  (See
 		debian/patches/README as there are some weird things here.)

