diff --git a/SConstruct b/SConstruct
index c14b97e1..41578a6b 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1,4 +1,13 @@
-
+from __future__ import print_function
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import unicode_literals
+
+from builtins import int
+from builtins import str
+from builtins import map
+from future import standard_library
+standard_library.install_aliases()
 import os
 import sys
 import subprocess
@@ -20,7 +29,7 @@ osname = os.getenv('BMS_OSNAME', 'build')
 
 # Get gcc major version
 proc=subprocess.Popen('./gccversion.sh', shell=True, stdout=subprocess.PIPE, )
-gcc_version_str=proc.communicate()[0]
+gcc_version_str=str(proc.communicate()[0], 'utf-8')
 gcc_version = int(gcc_version_str.rstrip("\n"))
 print('gcc_version =', gcc_version)
 
@@ -72,7 +81,7 @@ if SHOWBUILD==0:
 # Turn on debug symbols and warnings
 env.PrependUnique(      CFLAGS = ['-g', '-fPIC', '-Wall'])
 env.PrependUnique(    CXXFLAGS = ['-g', '-fPIC', '-Wall'])
-if gcc_version >= 9:
+if gcc_version >= 10:
    env.PrependUnique(FORTRANFLAGS = ['-g', '-fPIC', '-fallow-argument-mismatch'])
 else:
    env.PrependUnique(FORTRANFLAGS = ['-g', '-fPIC'])
diff --git a/SConstruct3 b/SConstruct3
deleted file mode 100644
index ca6d4caf..00000000
--- a/SConstruct3
+++ /dev/null
@@ -1,186 +0,0 @@
-
-import os
-import sys
-import subprocess
-import glob
-import SCons
-
-# XML files included in main_HDDS.xml (and others) that scons can't figure out for itself
-XMLDEPS = ['BarrelEMcal_HDDS.xml' , 'ForwardEMcal_HDDS.xml' , 'Solenoid_HDDS.xml'     ,
-           'BeamLine_HDDS.xml'    , 'StartCntr_HDDS.xml'    , 'CentralDC_HDDS.xml'    ,
-		   'ForwardTOF_HDDS.xml'  , 'Target_HDDS.xml'       , 'ComptonEMcal_HDDS.xml' ,
-		   'Material_HDDS.xml'    , 'DIRC_HDDS.xml'         , 'PairSpect_HDDS.xml'    ,
-		   'ForwardDC_HDDS.xml'   , 'Regions_HDDS.xml']
-
-# Get command-line options
-SHOWBUILD = ARGUMENTS.get('SHOWBUILD', 0)
-
-# Get platform-specific name
-osname = os.getenv('BMS_OSNAME', 'build')
-
-# Get gcc major version
-proc=subprocess.Popen('./gccversion.sh', shell=True, stdout=subprocess.PIPE, )
-gcc_version_str=str(proc.communicate()[0], 'utf-8')
-gcc_version = int(gcc_version_str.rstrip("\n"))
-print('gcc_version =', gcc_version)
-
-# Check for GDML support in ROOT
-hasGDMLsupport = False
-rootsys = os.getenv('ROOTSYS')  # needed to run root to generate GDML
-if rootsys != None:
-	if os.path.exists('%s/include/TGDMLWrite.h' % rootsys): hasGDMLsupport = True
-if hasGDMLsupport:
-	print('ROOT GDML support found. GDML files will be generated.')
-else:
-	print('No ROOT support for GDML. GDML files will NOT be generated.')
-
-# Setup initial environment
-builddir   = ".%s" % (osname)
-installdir = "#%s" %(osname)
-include    = "%s/include" % (installdir)
-bin        = "%s/bin" % (installdir)
-lib        = "%s/lib" % (installdir)
-env = Environment(ENV = os.environ,  # Bring in full environement, including PATH
-                  CXX         = os.getenv('CXX', 'c++'),
-                  CC          = os.getenv('CC' , 'cc'),
-                  FC          = os.getenv('FC' , 'gfortran'),
-                  CPPPATH     = ['.'])
-
-# Add Xerces
-xerces = os.getenv('XERCESCROOT')
-if xerces == None:
-	print('You MUST have your XERCESCROOT environment variable defined!')
-	sys.exit(-1)
-env.AppendUnique(CPPPATH=['%s/include' % xerces])
-env.AppendUnique(LIBPATH=['%s/lib' % xerces], LIBS=['xerces-c'])
-
-# Use terse output unless otherwise specified
-if SHOWBUILD==0:
-	env.Replace(   CCCOMSTR       = "Compiling  [$SOURCE]",
-				  CXXCOMSTR       = "Compiling  [$SOURCE]",
-				  FORTRANPPCOMSTR = "Compiling  [$SOURCE]",
-				  FORTRANCOMSTR   = "Compiling  [$SOURCE]",
-				  SHCCCOMSTR      = "Compiling  [$SOURCE]",
-				  SHCXXCOMSTR     = "Compiling  [$SOURCE]",
-				  LINKCOMSTR      = "Linking    [$TARGET]",
-				  SHLINKCOMSTR    = "Linking    [$TARGET]",
-				  ARCOMSTR        = "Archiving  [$TARGET]",
-				  RANLIBCOMSTR    = "Ranlib     [$TARGET]",
-				  INSTALLSTR      = "Installing [$TARGET]")
-
-
-# Turn on debug symbols and warnings
-env.PrependUnique(      CFLAGS = ['-g', '-fPIC', '-Wall'])
-env.PrependUnique(    CXXFLAGS = ['-g', '-fPIC', '-Wall'])
-if gcc_version >= 9:
-   env.PrependUnique(FORTRANFLAGS = ['-g', '-fPIC', '-fallow-argument-mismatch'])
-else:
-   env.PrependUnique(FORTRANFLAGS = ['-g', '-fPIC'])
-
-# Common source files used for all programs
-COMMONSRC = ['hddsCommon.cpp', 'XParsers.cpp', 'XString.cpp', 'md5.c']
-
-# Define source files for each program
-HDDSGEANTSRC = ['hdds-geant.cpp' ] + COMMONSRC
-HDDSROOTSRC  = ['hdds-root.cpp'  ] + COMMONSRC
-HDDSROOTHSRC = ['hdds-root_h.cpp'] + COMMONSRC
-HDDSMD5SRC   = ['hdds-md5.cpp'   ] + COMMONSRC
-FINDALLSRC   = ['findall.cpp', 'hddsBrowser.cpp'] + COMMONSRC
-
-# Prepend build directory to all sources so the .o files will
-# be stored in the platform specific build dir
-env.VariantDir(".%s" % (osname), '#', duplicate=0) 
-HDDSGEANTSRC = [builddir + '/' + s for s in HDDSGEANTSRC]
-HDDSROOTSRC  = [builddir + '/' + s for s in HDDSROOTSRC ]
-HDDSROOTHSRC = [builddir + '/' + s for s in HDDSROOTHSRC]
-HDDSMD5SRC   = [builddir + '/' + s for s in HDDSMD5SRC  ]
-FINDALLSRC   = [builddir + '/' + s for s in FINDALLSRC  ]
-COMMONBSRC   = [builddir + '/' + s for s in COMMONSRC   ]
-
-# Make programs
-hdds_geant  = env.Program(target='%s/hdds-geant'  % builddir, source=HDDSGEANTSRC )
-hdds_rootc  = env.Program(target='%s/hdds-root'   % builddir, source=HDDSROOTSRC  )
-hdds_rooth  = env.Program(target='%s/hdds-root_h' % builddir, source=HDDSROOTHSRC )
-hdds_md5    = env.Program(target='%s/hdds-md5'    % builddir, source=HDDSMD5SRC   )
-findall     = env.Program(target='%s/findall'     % builddir, source=FINDALLSRC   )
-
-# ---- Create builders to generate source using hdds programs ---
-if SHOWBUILD==0:
-	hddsgeantaction = SCons.Script.Action("%s/hdds-geant  $SOURCE > $TARGET" % (builddir), 'HDDS-GEANT [$SOURCE -> $TARGET]')
-	hddsrootaction  = SCons.Script.Action("%s/hdds-root   $SOURCE > $TARGET" % (builddir), 'HDDS-ROOTC [$SOURCE -> $TARGET]')
-	hddsroothaction = SCons.Script.Action("%s/hdds-root_h $SOURCE > $TARGET" % (builddir), 'HDDS-ROOTH [$SOURCE -> $TARGET]')
-	if hasGDMLsupport:
-		hddsgdmlaction  = SCons.Script.Action('%s/bin/root -b -q $SOURCE "mkGDML.C(\\"$TARGET\\")" > /dev/null 2>&1' % (rootsys) , 'HDDS-GDML  [$SOURCE -> $TARGET]')
-else:
-	hddsgeantaction = SCons.Script.Action("%s/hdds-geant  $SOURCE > $TARGET" % (builddir))
-	hddsrootaction  = SCons.Script.Action("%s/hdds-root   $SOURCE > $TARGET" % (builddir))
-	hddsroothaction = SCons.Script.Action("%s/hdds-root_h $SOURCE > $TARGET" % (builddir))
-	if hasGDMLsupport:
-		hddsgdmlaction  = SCons.Script.Action('%s/bin/root -b -q $SOURCE "mkGDML.C(\\"$TARGET\\")"' % (rootsys))
-hddsgeantbld = SCons.Script.Builder(action = hddsgeantaction )
-hddsrootbld  = SCons.Script.Builder(action = hddsrootaction  )
-hddsroothbld = SCons.Script.Builder(action = hddsroothaction )
-env.Append(BUILDERS = {'HDDSgeant'  : hddsgeantbld })
-env.Append(BUILDERS = {'HDDSrootc'  : hddsrootbld  })
-env.Append(BUILDERS = {'HDDSrooth'  : hddsroothbld })
-if hasGDMLsupport:
-	hddsgdmlbld  = SCons.Script.Builder(action = hddsgdmlaction  )
-	env.Append(BUILDERS = {'HDDSgdml'   : hddsgdmlbld  })
-
-# --- Use builders to generate source from XML ---
-if os.getenv('LD_LIBRARY_PATH'  ) != None : env.AppendENVPath('LD_LIBRARY_PATH'  , '%s/lib' % xerces )  # so libxerces-c.so can be found
-if os.getenv('DYLD_LIBRARY_PATH') != None : env.AppendENVPath('DYLD_LIBRARY_PATH', '%s/lib' % xerces )  # so libxerces-c.so can be found
-HDDSGEANT3 = env.HDDSgeant(target='%s/hddsGeant3.F' % builddir, source=['main_HDDS.xml']+XMLDEPS)
-HDDSROOTC  = env.HDDSrootc(target='%s/hddsroot.C'   % builddir, source=['main_HDDS.xml']+XMLDEPS)
-HDDSROOTH  = env.HDDSrooth(target='%s/hddsroot.h'   % builddir, source=['main_HDDS.xml']+XMLDEPS)
-CPPROOTC   = env.HDDSrootc(target='%s/cpproot.C'    % builddir, source=['cpp_HDDS.xml','TargetCPP_HDDS.xml','ForwardMWPC_HDDS.xml']+XMLDEPS)
-CPPROOTH   = env.HDDSrooth(target='%s/cpproot.h'    % builddir, source=['cpp_HDDS.xml','TargetCPP_HDDS.xml','ForwardMWPC_HDDS.xml']+XMLDEPS)
-if hasGDMLsupport:
-	HDDSGDML   = env.HDDSgdml( target='%s/hddsroot.gdml' % builddir, source='%s/hddsroot.C' % builddir)
-	CPPGDML    = env.HDDSgdml( target='%s/cpproot.gdml' % builddir, source='%s/cpproot.C' % builddir)
-env.Requires([HDDSGEANT3], hdds_geant)
-env.Requires([HDDSROOTC] , hdds_rootc)
-env.Requires([HDDSROOTH] , hdds_rooth)
-env.Requires([CPPROOTC]  , hdds_rootc)
-env.Requires([CPPROOTH]  , hdds_rooth)
-if hasGDMLsupport:
-	env.Requires([HDDSGDML]  , HDDSROOTC  )
-	env.Requires([CPPGDML]   , CPPROOTC  )
-
-# --- Build libhddsGeant3.a
-if os.getenv('CERN'):
-	libhddsgeant3 = env.Library(target='%s/hddsGeant3' % builddir, source=HDDSGEANT3)
-libhdds = env.SharedLibrary(target='%s/hdds' % builddir, source = COMMONBSRC, SHLIBSUFFIX='.so')
-
-# Configure for installation. In principle, we should not need to explicitly
-# check if the "install" target was specified. For some unknown reason though,
-# scons seems to install things automatically otherwise (Argghh!)
-build_targets = list(map(str,BUILD_TARGETS))
-if len(build_targets)>0:
-	if 'install' in build_targets:
-		env.Install(bin, hdds_geant)
-		env.Install(bin, hdds_rootc)
-		env.Install(bin, hdds_rooth)
-		env.Install(bin, hdds_md5)
-		env.Install(bin, findall)
-
-		env.Install('%s/src' % installdir, HDDSGEANT3)
-		env.Install('%s/src' % installdir, HDDSROOTC)
-		env.Install('%s/src' % installdir, HDDSROOTH)
-		env.Install('%s/src' % installdir, CPPROOTC)
-		env.Install('%s/src' % installdir, CPPROOTH)
-		if hasGDMLsupport:
-			env.Install('%s/src' % installdir, HDDSGDML)
-			env.Install('%s/src' % installdir, CPPGDML)
-
-		if os.getenv('CERN'): env.Install(lib, libhddsgeant3)		
-		env.Install(lib, libhdds)		
-
-# Make install target
-env.Alias('install', installdir)
-
-
-
-
-
-