gnucash: /usr/lib/gnucash/libgnc-backend-postgres.so: cannot open shared object file: No such file or directory

failed to load gnc-backend-postgres from /usr/lib/gnucash

loading system configuration
looking for /etc/gnucash/config
trying to load /etc/gnucash/config
loading user configuration
looking for /home/res/jmd/.gnucash/config-2.0.user
looking for /home/res/jmd/.gnucash/config-1.8.user
looking for /home/res/jmd/.gnucash/config-1.6.user
looking for /home/res/jmd/.gnucash/config.user
loading auto configuration
looking for /home/res/jmd/.gnucash/config-2.0.auto
looking for /home/res/jmd/.gnucash/config-1.8.auto
trying to load /home/res/jmd/.gnucash/config-1.8.auto
/home/res/jmd/.gnucash/config-1.8.auto:34:15: While evaluating arguments to gnc:lookup-option in expression (gnc:lookup-option gnc:*options-entries* "__tips" ...):
/home/res/jmd/.gnucash/config-1.8.auto:34:15: Unbound variable: gnc:*options-entries*
In /home/res/jmd/.gnucash/config-1.8.auto:
  34: 0* (let ((option #)) ((lambda # #) option))
  34: 1* [gnc:lookup-option ...

looking for /home/res/jmd/.gnucash/config-1.6.auto
looking for /home/res/jmd/.gnucash/config.auto
loading saved reports
looking for /home/res/jmd/.gnucash/saved-reports-2.0
looking for /home/res/jmd/.gnucash/saved-reports-1.8
loading stylesheets
looking for /home/res/jmd/.gnucash/stylesheets-2.0
trying to load /home/res/jmd/.gnucash/stylesheets-2.0
Warning: gnc_file_be_load_from_file(): File not any known type