RCS needs diff(1) and diff3(3) to generate the
context diff files between revisions. The diff utilities suite needs
to be installed on your system, and when you install RCS, the software
will check for its presence.
Precompiled diffutils binaries are available at:
ftp://sunsite.unc.edu/pub/Linux/utils/text/diffutils-2.6.bin.ELF.tar.gzand its mirror sites. If you need to compile
diff(1), et
al., from source, it is located at:
ftp://prep.ai.mit.edu/pub/gnu/diffutils-2.7.tar.gzand its mirror sites.
You will also need to have the ELF libraries installed on your system if you want to install pre-built binaries. See the ELF-HOWTO for further details.