BUG #13258: pg_config shows wrong version

The following bug has been logged on the website:

Bug reference:      13258
Logged by:          Abraham Polishchuk
Email address:      apolishc@gmail.com
PostgreSQL version: 9.3.0
Operating system:   Ubuntu
Description:

Hi,

I am using Postgres 9.3, however my pg_config points at 9.4, preventing me
from building extensions (pgTap).

$ sudo aptitude search postgresql | grep ^i
i   postgresql-9.3                  - object-relational SQL database,
version 9.
i   postgresql-client-9.3           - front-end programs for PostgreSQL 9.3

i A postgresql-client-common        - manager for multiple PostgreSQL client
ver
i A postgresql-common               - PostgreSQL database-cluster manager

i   postgresql-contrib-9.3          - additional facilities for PostgreSQL


$ pg_config
BINDIR = /usr/lib/postgresql/9.4/bin
DOCDIR = /usr/share/doc/postgresql-doc-9.4
HTMLDIR = /usr/share/doc/postgresql-doc-9.4
INCLUDEDIR = /usr/include/postgresql
PKGINCLUDEDIR = /usr/include/postgresql
INCLUDEDIR-SERVER = /usr/include/postgresql/9.4/server
LIBDIR = /usr/lib/x86_64-linux-gnu
PKGLIBDIR = /usr/lib/postgresql/9.4/lib
LOCALEDIR = /usr/share/locale
MANDIR = /usr/share/postgresql/9.4/man
SHAREDIR = /usr/share/postgresql/9.4
SYSCONFDIR = /etc/postgresql-common
PGXS = /usr/lib/postgresql/9.4/lib/pgxs/src/makefiles/pgxs.mk
CONFIGURE = '--with-tcl' '--with-perl' '--with-python' '--with-pam'
'--with-openssl' '--with-libxml' '--with-libxslt'
'--with-tclconfig=/usr/lib/tcl8.5' '--with-includes=/usr/include/tcl8.5'
'PYTHON=/usr/bin/python' '--mandir=/usr/share/postgresql/9.4/man'
'--docdir=/usr/share/doc/postgresql-doc-9.4'
'--sysconfdir=/etc/postgresql-common' '--datarootdir=/usr/share/'
'--datadir=/usr/share/postgresql/9.4' '--bindir=/usr/lib/postgresql/9.4/bin'
'--libdir=/usr/lib/x86_64-linux-gnu/' '--libexecdir=/usr/lib/postgresql/'
'--includedir=/usr/include/postgresql/' '--enable-nls'
'--enable-integer-datetimes' '--enable-thread-safety' '--enable-debug'
'--disable-rpath' '--with-uuid=e2fs' '--with-gnu-ld' '--with-pgport=5432'
'--with-system-tzdata=/usr/share/zoneinfo' 'CFLAGS=-g -O2 -fstack-protector
--param=ssp-buffer-size=4 -Wformat -Wformat-security -Werror=format-security
-I/usr/include/mit-krb5 -fPIC -pie -DLINUX_OOM_SCORE_ADJ=0
-fno-omit-frame-pointer' 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro
-Wl,-z,now -Wl,--as-needed -L/usr/lib/mit-krb5
-L/usr/lib/x86_64-linux-gnu/mit-krb5' '--with-krb5' '--with-gssapi'
'--with-ldap' 'CPPFLAGS=-D_FORTIFY_SOURCE=2'
CC = gcc
CPPFLAGS = -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -I/usr/include/libxml2
-I/usr/include/tcl8.5
CFLAGS = -Wall -Wmissing-prototypes -Wpointer-arith
-Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute
-Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard
-g -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat
-Wformat-security -Werror=format-security -I/usr/include/mit-krb5 -fPIC -pie
-DLINUX_OOM_SCORE_ADJ=0 -fno-omit-frame-pointer
CFLAGS_SL = -fpic
LDFLAGS = -L../../../src/common -Wl,-Bsymbolic-functions -Wl,-z,relro
-Wl,-z,now -Wl,--as-needed -L/usr/lib/mit-krb5
-L/usr/lib/x86_64-linux-gnu/mit-krb5 -L/usr/lib/x86_64-linux-gnu
-Wl,--as-needed
LDFLAGS_EX =
LDFLAGS_SL =
LIBS = -lpgcommon -lpgport -lxslt -lxml2 -lpam -lssl -lcrypto -lgssapi_krb5
-lz -ledit -lrt -lcrypt -ldl -lm
VERSION = PostgreSQL 9.4.1


Any thoughts on what could be causing this and/or any workarounds would be
awesome.

Thanks,
Abe