Wayland

This material needs expanding ... A more thorough guide to installing, configuring, and running wayland on Alpine would be better.

Wayland is a new display protocol that aims to replace X11.

XDG_RUNTIME_DIR

As per the protocol spec, Wayland compositors require the XDG_RUNTIME_DIR variable to be set. A login manager such as Elogind can configure this and other Freedesktop.org environment variables automatically.

Generally it's inadvisable to configure XDG_* variables manually as this configuration may have errors or conflict with other utilities that do this automatically. That said, it is possible to configure XDG_RUNTIME_DIR adding the following snippet to shell init scripts (e.g.: ~/.profile):

if test -z "${XDG_RUNTIME_DIR}"; then
  export XDG_RUNTIME_DIR=/tmp/$(id -u)-runtime-dir
  if ! test -d "${XDG_RUNTIME_DIR}"; then
    mkdir "${XDG_RUNTIME_DIR}"
    chmod 0700 "${XDG_RUNTIME_DIR}"
  fi
fi