TIP : building firebird 2.5 from source remove /tmp/firebird folder

before doing make install is better to remove the /tmp/firebird if is owned by root

with 2.5.0 i had this error
 ConfigStorage: Cannot initialize the shared memory region
        operating system directive open failed
        Permission denied 


So i have checked out the 2.5.1 from svn/bzr
bzr branch lp:firebird/2.5
cd 2.5
./autogen.sh --prefix=/opt/firebird2.5.x --enable-superserver --with-system-editline
make
stop firebird
rm -rf /tmp/firebird
make install

now firebird runs happily on CentOS release 5.5