Problem

When adding /mnt/hgfs/shared/e/steam (also connected to Windows Steam) to Downloads + cloud → Steam library folders → Add library folder the dialog return New Steam library folder must be empty.

The purpose is to use the same gcf folder for both clients.

Discussion

• What's the purpose of this restriction?
• How do I work around this by adding the setting directly to the setting file? (Where is the setting stored?)

Workaround

• Use a folder link instead

s=~/.local/share/Steam/SteamApps; rm -rf $s; ln -s /mnt/hgfs/shared/e/steam $s

• Move the contents from the intended folder before changing this setting and move them back after changing the setting.