9.4 and centos/yum multiversion installs

I have a CentOS 6 server thats already running 9.0, ... 9.3 for development.

I added 9.4 to it by ...
yum install
http://yum.postgresql.org/9.4/redhat/rhel-6-x86_64/pgdg-centos94-9.4-1.noarch.rpm
yum install postgresql94{,-devel,-server,-contrib}

I created /etc/sysconfig/pgsql/postgresql-9.4 with...
PGENGINE=/usr/pgsql-${PGMAJORVERSION}/bin
PGPORT=5436
PGDATA=/var/lib/pgsql/${PGMAJORVERSION}/data
PGLOG=/var/lib/pgsql/${PGMAJORVERSION}/pgstartup.log

(same as all the others except a unique port)
and initdb via..
service postgresql-9.4 initdb

all good so far. but when I ...

service postgresql-9.4 start

it fails, leaving the following in pgstartup.log...

< 2015-09-29 09:38:15.270 PDT >LOG: could not bind IPv6 socket:
Address already in use
< 2015-09-29 09:38:15.270 PDT >HINT: Is another postmaster already
running on port 5432? If not, wait a few seconds and retry.
< 2015-09-29 09:38:15.270 PDT >LOG: could not bind IPv4 socket:
Address already in use
< 2015-09-29 09:38:15.270 PDT >HINT: Is another postmaster already
running on port 5432? If not, wait a few seconds and retry.
< 2015-09-29 09:38:15.270 PDT >WARNING: could not create listen
socket for "localhost"
< 2015-09-29 09:38:15.270 PDT >FATAL: could not create any TCP/IP
sockets

does the 9.4 yum install no longer support using the sysconfig settings
fragments ? I see what looks like the correct shell code for it in
/etc/rc.d/init.d/postgresql-9.4 ...

# Override defaults from /etc/sysconfig/pgsql if file is present
[ -f /etc/sysconfig/pgsql/${NAME} ] && . /etc/sysconfig/pgsql/${NAME}

....arrrrgh, comment in /etc/rc.d/init.d/postgresql-9.4 would suggest so...

# Version 9.4.0 Devrim Gunduz <devrim(at)gunduz(dot)org>
# Remove PGPORT variable

so... how do you run multiple versions??

--
john r pierce, recycling bits in santa cruz