problem installing bird 2.0.1

[Mattia Milani]

Hello, i'm trying to istall bird 2.0.1 from github source code, but i found
some problems.

command ./configure exited correctly with no problem.
command make exited with a lot of warinings but without error.
command make install exited with this:

/usr/bin/install -c -d //usr/local/sbin //usr/local/etc //usr/local/var/run
/usr/bin/install -c ../bird //usr/local/sbin/bird
/usr/bin/install -c ../birdcl //usr/local/sbin/birdcl
if test -n "birdc" ; then                                \
    /usr/bin/install -c ../birdc //usr/local/sbin/birdc ;    \
fi
if ! test -f //usr/local/etc/bird.conf ; then                        \
    /usr/bin/install -c -m 644 ../doc/bird.conf.example
//usr/local/etc/bird.conf ;\
else                                            \
    echo "Not overwriting old bird.conf" ;                    \
fi
Not overwriting old bird.conf

and i can't understood how to correct this error and compleate the
installation

before intalling the latest version of bird I removed bird 1.6.3 that was
working with no problems.

Thanks,
Mattia