When debugging serial ports, it's common to kill all c-s-c daemons and then start a new one, with debugging to stdout. If doing this from a TL sessions that has tl-serial-redir in xstartup.d, c-s-c will try to "redirect itself", since LD_PRELOAD and CYCLADES_DEVICES is already set. This doesn't work: c-s-c fails init with a lot of errors about partial reads etc. I think c-s-c check check for this environment and avoid it or exit with an error.