Your system information

• Steam client version (build number or date):
• Distribution (e.g. Ubuntu): Gentoo (5.10.49-gentoo-r1)
• Opted into Steam client beta?: Yes
• Have you checked for system updates?: Yes

Please describe your issue in as much detail as possible:

Describe what you expected should happen and what did happen. Please link any large code pastes as a Github Gist
I expected to be met with my library but I got a black screen. Nothing that relied on webview works. I can alter the settings but not open the store, library, community or friends.

My steamwebhelper.log contained the following:

Updating Steam runtime environment...
/home/peter/.local/share/Steam/ubuntu12_64/steam-runtime-heavy/setup.sh: line 421: zenity: command not found
/home/peter/.local/share/Steam/ubuntu12_64/steam-runtime-heavy/setup.sh: line 77: echo: write error: Broken pipe

Steps for reproducing this issue:

1. Update steam
2. Login