On Sat, 17 Feb 2018, Pavel Sanda wrote:
For the record, it turned out that High Sierra is no more compatible with old RCS binaries (if you manually run co -l file.lyx you get "Illegal instruction: 4"). Compiling RCS via homebrew fixed the problem.
Pavel, If subversion, mercurial, or git are available for Macs they are more modern than RCS. Have you considered them? Rich
