The following bug has been logged on the website:
Bug reference: 10700
Logged by: Bodor András
Email address: bodri(dot)mh3(at)gmail(dot)com
PostgreSQL version: 9.4beta1
Operating system: Debian wheezy
Description:
To install postgresql-client-9.4 using
the postgres debian apt repository, the
package depends on libpq5(>= 9.4~beta1)
however only 9.3.4-1.pgdg70+1 is
available.