new steam library must be on a filesystem mounted with execute permissions

Solution 1:

I was recently having an issue with Steam not having execute permissions on a mounted filesystem, I found what the actual problem was due to how the folders are named.

In your home directory you have two folder locations for Steam;

.steam/steam/SteamApps

and

.local/share/Steam/SteamApps

by default games will install under .local/share/Steam/SteamApps unless you have chosen another directory from within Steam client. The problem is Steam client is trying to look for games and software under SteamApps directory, but this directory name is Upper and Lower Case name, it needs to be Lower Case name so all you just need to really do is make a symbolic link to that folder like so;

ln -s SteamApps steamapps

this should hopefully resolve the issues with executable permissions error in Steam when trying to add a directory, be sure to close and/or restart Steam after doing this. This is just all how Valve sorted Steam to do SteamPipe for Source games for better management of installs and adding mods to games; https://developer.valvesoftware.com/wiki/SteamPipe