Prerequisites for building gcc-10.2 on clean Fedora 33 (64-bit)

If you've tried building GCC 10.2 from source and get this message:

configure: error: Building GCC requires GMP 4.2+, MPFR 3.1.0+ and MPC 0.8.0+.

Then just install the following packages...

[user]$ sudo dnf install gmp-devel mpfr-devel libmpc-devel

If you then see:

configure: error: I suspect your system does not have 32-bit development libraries (libc and headers). If you have them, rerun configure with --enable-multilib. If you do not have them, and want to build a 64-bit-only compiler, rerun configure with --disable-multilib.

Do:

[user]$ sudo dnf install glibc-devel.i686

Altogether:

[user]$ sudo dnf install gmp-devel mpfr-devel libmpc-devel glibc-devel.i686