I also installed Steam on Debian Sid. There is a known problem with the Steam bootloader and closed source video card drivers (NVidia and AMD). The current workaround is to install Steam using the open source driver (xserver-xorg-video-radeon for AMD), log into Steam, then install the closed source driver. The fglrx-driver from repos is using the closed source driver. Not sure what it is for Nvidia cuz I only own AMD.
I have nVidia card and an nVidia blob. I will retry with nouveau driver enabled.
Just writing a follow-up to your last comment. Did you have any success installing Steam using the open source driver?
Yes, it works with nouveau driver.
I have a similar issue on a 32-bit system after update/upgrading to latest sid yesterday (April 17).
I also get "Error: You are missing the following 32-bit libraries, and Steam may not run: libc.so.6"
Then if you look deeper you find that ldd reports "/lib/i386-linux-gnu/libncurses.so.5: undefined symbol: _nc_putchar" and thats why it fails.
I have tried reinstalling all the nvidia driver stuff but that didn't help. I will try to activate nouveau driver and see if it works later.
Closing as duplicate.
Nothing extracted yet.
Trying to install Steam on a freshly updated Debian testing i386.
Steam client downloads runtime, unpacks it and then crashes straight ahead:
I tried to workaround #3252 by providing a copy of Ubuntu's libncurses5.so. The warning about libc.so.6 is gone, however the crash still persists: