can't run epiphany after building it from source

I'm trying to modify epiphany to include a feature that I want it to have.

I've tried 2 ways to build it after I've made my changes:

Try 1:
$ apt-get source epiphany-browser
$ sudo apt-get build-dep epiphany-browser
$ cd epiphan*
$ ./autogen.sh
$ ./configure
$ make
$ make install
$ /usr/local/bin/epiphany

I get an error saying that mozilla could not be started at this time.

Try 2:
$ apt-get source epiphany-browser
$ sudo apt-get build-dep epiphany-browser
$ dpkg-buildpackage -rfakeroot -uc -b

And I get a build error.

Can someone tell me the right way to build epiphany after i've made my own changes to the source?

Thanks!