Have a MIRAL_WINDOW_MANAGEMENT_TRACE env var

[Gerry Boland]

We're struggling to get command line argument processing working reliably with mir/miral and unity8, to the extent that we're going to stop passing args to mir entirely (until we can have another attempt).

Mir at least has mirroring env vars for all command line arguments.
Could MirAL also have that for --window_management_trace

[Alan Griffiths (alan-griffiths)]

MirAL uses the Mir command line processing. That means: in addition to a command line you can also use:

/1/ a config file (third parameter to MirRunner constructor or deduced from argv[0])

$ cat ~/.config/miral-shell.config
x11-displays=1200x900
keymap=gb
window-management-trace=

/2/ MIR_SERVER_<upppercase version of commandline>

MIR_SERVER_WINDOW_MANAGEMENT_TRACE=anything