The original guide seems not to work anymore. The problem is that the requested cross compiler is not found by distccd. The following workaround solves this issue: in /etc/init.d/distccd the PATH environment variable is altered before starting the daemon. This is the full command:

TMPDIR="${TMPDIR}" \
PATH="$(gcc-config --get-bin-path):${PATH}" \
/sbin/start-stop-daemon --start --quiet --startas ${DISTCCD_EXEC} \
--pidfile ${DISTCCD_PIDFILE} -- \
--pid-file ${DISTCCD_PIDFILE} -N
${DISTCCD_NICE} --user distcc \
${DISTCCD_OPTS}

the problem here is that gcc-config –get-bin-path only returns the search path for the currently active profile, not all available profiles (the cross compiler is a profile on it's own). So for every installed cross compiler gcc-config has to be called again given the correct profile number:

TMPDIR="${TMPDIR}" \
PATH="$(gcc-config --get-bin-path):$(gcc-config --get-bin-path 1):${PATH}" \
/sbin/start-stop-daemon --start --quiet --startas ${DISTCCD_EXEC} \
--pidfile ${DISTCCD_PIDFILE} -- \
--pid-file ${DISTCCD_PIDFILE} -N
${DISTCCD_NICE} --user distcc \
${DISTCCD_OPTS}

The original Gentoo guide