The kernel now needs to use GNU bc to be built since version 3.9. The following
commit message from the kernel explains the reason:
Author: H. Peter Anvin <email@example.com>
Date: Thu Feb 14 15:13:55 2013 -0800
kernel: Replace timeconst.pl with a bc script
bc is the standard tool for multi-precision arithmetic. We switched
to Perl because akpm reported a hard-to-reproduce build hang, which
was very odd because affected and unaffected machines were all running
the same version of GNU bc.
Unfortunately switching to Perl required a really ugly "canning"
mechanism to support Perl < 5.8 installations lacking the Math::BigInt
It was recently pointed out to me that some very old versions of GNU
make had problems with pipes in subshells, which was indeed the
construct used in the Makefile rules in that version of the patch;
Perl didn't need it so switching to Perl fixed the problem for
unrelated reasons. With the problem (hopefully) root-caused, we can
switch back to bc and do the arbitrary-precision arithmetic naturally.
Signed-off-by: H. Peter Anvin <firstname.lastname@example.org>
Cc: Andrew Morton <email@example.com>
Acked-by: Sam Ravnborg <firstname.lastname@example.org>
Signed-off-by: Michal Marek <email@example.com>
Signed-off-by: Lucas Dutra Nunes <firstname.lastname@example.org>