Building 32bit ROOT on 64bit Ubuntu 14.04.01

Dear Rooters,

I need to build a 32bit ROOT (5.34.20 or 6.00.02) on Ubuntu 14.04.01, gcc 4.8
(because I link to CERNLIBs ZEBRA) but have only a 64bit system available.
Has anybody a “simple” recipe to achieve this.
The current “configure” seems only to support cross compilation for ios


Some people claim that they are able to use ZEBRA on a 64-bit machine using the “Desy’s CERNLIB 2005 distribution”.
Actually, I think you should also be able to use the default CERNLIB 2006 provided by your Ubuntu (which is probably much better maintained then the “Desy’s CERNLIB 2005 distribution”).
Note: you need to use static CERNLIB libraries (not shared) and the “-fno-automatic” flag of gfortran. See, for example, this “README.64-bit” file.

Hi Wile,

thanks for the answer. In fact I know of this activity with 64bit CERNLIB.
However my project ( … pengl.html)
not only involves CERNLIB but nearly the complete reconstruction software of the former
LEP experiment OPAL. Therefore I dont dare to change to 64bit.

If I dont find a simple way to crossbuild ROOT I will install a 32bit Ubuntu in a Virtual Box.
At the end it is a question of minimizing the work.


Well, you can try to enforce 32-bit x86 ROOT build using:
./configure linux