it seems that there is a regression the the PostgreSQL 9.5 RPMs for CentOS (possibly others). The problem occurs when trying to install postgresql95-server using yum from http://yum.postgresql.org/9.5/redhat/rhel-7-x86_64/. In the post installation phase, a message like this:
/var/tmp/rpm-tmp.jvPp3e: line 10: fg: no job control
is printed. This leaves the systemd setup of the server incomplete and it cannot be started.
With the help of Zr40 in IRC, I could determine that the problem was introduced in http://git.postgresql.org/gitweb/?p=pgrpms.git;a=commitdiff;h=d52487 which added a "%tmpfiles_createa" line to the post install steps which seems not to be resolved by RPM, leaving a stray % in the script which causes the message. See "rpm -q --scripts postgresql95-server-9.5.1" for the scripts.
I'll go back to PostgreSQL 9.4 for now, but I'd be interested in upgrading.