3.6 Can Debian be used to compile libc5 programs?

Yes. Install libc5-altdev and altgcc packages (from the oldlibs section). You can find the appropriate libc5-compiled gcc and g++ in directory /usr/i486-linuxlibc1/bin. Put them in your $PATH variable to get make and other programs to execute these first.

Be aware that libc5 environment isn't fully supported by our other packages anymore.