Source tarball is missing `sass` folder which makes it impossible to re-build some generated files.
Moreover 3.0.4 source tarball contains source-less minified `frontends/php/styles/*-theme.css` files.
Effectively minified code is equivalent of pre-compiled binary – un-readable, non-modifiable and non-distributable in Debian.
Please do not minify CSS files for source releases.
Please replace all minified files with their original (non-minified) sources (as it was in 3.0.3 and prior releases).
Read more in https://wiki.debian.org/onlyjob/no-minification
Also please ship all sources in source tarball, including `sass` folder.