*******@*******-PC:~$ steam
Running Steam on ubuntu 15.04 64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(0)
This happens when a lib is missing. You may want to read this related question on askubuntu (http://askubuntu.com/questions/614422/problem-with-installing-steam-on-ubuntu-15-04)
Did you fix it?
I recall steam working out of the box on Ubuntu 14.04LTS. Hmm probably a dropped lib that is not included in 15 anymore.
You could try playonlinux, it includes steam in it's install, maybe it does stuff differently.
I can't recommend steam on debian. A lot of missing stuff no fun at all to install.
The snippet you posted does not actually include the error. Those messages are just logging messages. You'll need to post the rest of the lines. If indeed it is a missing library you can find out which package to install to get it, with apt-file (not installed by default).