Can you post this as a new bug report? It's a problem on the Inkscape side of the ppa / build process, and not a downstream packaging problem (and also add this info: for Ubuntu 16.04, libpoppler58 is available, while 61 is not, so hopefully it is not exchanged, but rather both versions should be allowed - else it won't work on the LTS version anymore).
You can also just copy the whole share/... folder from the repo, meanwhile (and remove the ppa, use the version from Ubuntu repos).
@rot13: Ah, that's unfortunate...
Can you post this as a new bug report? It's a problem on the Inkscape side of the ppa / build process, and not a downstream packaging problem (and also add this info: for Ubuntu 16.04, libpoppler58 is available, while 61 is not, so hopefully it is not exchanged, but rather both versions should be allowed - else it won't work on the LTS version anymore).
You can also just copy the whole share/... folder from the repo, meanwhile (and remove the ppa, use the version from Ubuntu repos).