build squid3 on Ubuntu

apt-get update
apt-get install devscripts build-essential
apt-get source squid3
apt-get build-dep squid3
cd squid3-"version"
nano debian/rules # or whatever editor you use
add the --enable-icap-client line among the other --enable-blah- lines
debuild -us -uc
cd ..
dpkg -i your_built_package.deb