oscar : Depends: libdouble-conversion3 but it is not installable
I was able to fix this on my ASUS chromebook by finding the libdouble-conversion3 debian package here:
https://debian.pkgs.org/sid/debian-main-...4.deb.html
Note that my chromebook uses amd64 processor packages, if your chromebook is an amr processor you'll need a different package.
After installing the library, I was able to install and then run OSCAR. I didn't grab the entire log from my terminal so can't provide the exact command output, but thought this might be helpful for someone trying to get OSCAR running on a chromebook.