bug#37942: Insufficient environment wrappers

[Leo Prikler]

Some packages -- such as meld after the startup fix -- fail to use
important resources when simply called from their build directory. For
instance, meld aborts inside a call to `g_log` by
`g_settings_set_property`. In the case of meld, it is sufficient to run
the program inside an ad-hoc environment -- other packages may require
to be installed in the user profile.

Regards,

Leo