I can confirm this issue.
It works as intended. Manjaro's binary sets STEAM_FRAME_FORCE_CLOSE to 0 for compatibility with DEs that don't have trays.
You need to edit /usr/bin/steam instead.
Thanks for figuring this out @petete1, this issue needs to be evaluated by Manjaro's package maintainer for Steam.
Nothing extracted yet.
Your system information
Please describe your issue in as much detail as possible:
Since several month the STEAM_FRAME_FORCE_CLOSE environment variable doesn't seem to have any effect anymore. I have it set to 1 but steam still only minimizes to the taskbar when clicking the close button and does not close to tray.
Possible related with this update: http://store.steampowered.com/news/26953/
However removing the STEAM_FRAME_FORCE_CLOSE environment variable altogether, as that update text might suggest, also yields no effect.
However starting steam with -silent argument starts it minimized to tray, but only till you first open the frame. Then it's stuck to the taskbar again.
Steps for reproducing this issue: