Hello. In addition to what Lucas reported, this package fails to build for me on amd64:
82% of the time on machines with 1 CPU 6% of the time on machines with 2 CPUs so maybe the issue is not about amd64/i386 but about overall speed. I suggest that you try on your normal amd64 system using GRUB_CMDLINE_LINUX="nr_cpus=1". If that does not work please contact me privately, as I can offer a VM where this high failure rate happens consistently. Thanks.