Can't install in global /usr/share/gnome-shell/extensions (Error Permission denied)

[ainiml]

Installing in global location /usr/share/gnome-shell/extensions fails

But installing in user directory works ~/.local/share/gnome-shell/extensions

GLib.FileError: Failed to open file “/usr/share/gnome-shell/extensions/window_buttons@biox.github.com/schemas/gschemas.compiled”: open() failed: Permission denied

Stack trace:
  getSettings@/usr/share/gnome-shell/extensions/window_buttons@biox.github.com/convenience.js:74:24
  WindowButtonsPrefsWidget<._init@/usr/share/gnome-shell/extensions/window_buttons@biox.github.com/prefs.js:110:26
  wrapper@resource:///org/gnome/gjs/modules/_legacy.js:82:22
  buildPrefsWidget@/usr/share/gnome-shell/extensions/window_buttons@biox.github.com/prefs.js:382:18
  _selectExtension@resource:///org/gnome/shell/extensionPrefs/main.js:91:22
  wrapper@resource:///org/gnome/gjs/modules/_legacy.js:82:22
  _onCommandLine@resource:///org/gnome/shell/extensionPrefs/main.js:243:17
  wrapper@resource:///org/gnome/gjs/modules/_legacy.js:82:22
  main@resource:///org/gnome/shell/extensionPrefs/main.js:397:5
  @<main>:1:43

Permissions:

-rw-r--r-- 1 root root 1.3K Jul 13 01:10 gschemas.compiled

chmod 666, still fails:

-rw-rw-rw- 1 root root 1.3K Jul 13 01:10 gschemas.compiled