Comment 10 for bug 1638373

@Filip and Jakub: It appears that almost all svg files in the /usr/share/inkscape directory have been modified in the package for your version of Ubuntu.

So if you're missing a filter, or a symbol set, a pattern or whatever, you can apply the same solution, only copying a different file from the repo into a different directory.

Location for the files:
http://bazaar.launchpad.net/~inkscape.dev/inkscape/RELEASE_0_91_BRANCH/files/head:/share/

Or you can use the Inkscape version from the ppa:
https://launchpad.net/~inkscape.dev/+archive/ubuntu/stable