Welcome to LQ. .. ..
Not quite clear, why you mention libc6-dev-i386, when you have a 64 bits Ubuntu ?
libc6-dev is automatically installed, when you install g++.
Is any 32 bits 'binutils' / 'g++-multilib' installed ? ? And why ?
Your errors seems to indicate an impossible situation :
The "64 bits linker (ld)" is used to link objcts created by a "32 bits g++".
Building the files .....
1) First the install of the CLHEP libraries :
cd 22.214.171.124/CLHEP/ && ./configure && make && sudo make install && exit
cd geant4.9.3.p01/ && ./Configure -build
Which configuration are you using ? And which commands ?
Ubuntu, is based on "Debian Sid".
I used the 64 bits Debian Sid for the Geant4 build test. Got no errors at all.
Which Ubuntu are you using ? ?