WARNING: Couldn't find the global config file.

[Jonathan Wakely]

The manual is pretty clear that the global site.exp config file is
optional, so why does runtest insist on shouting at me when it's not
set?

WARNING: Couldn't find the global config file.

I know I can set DEJAGNU=/dev/null but why do I need to? It's supposed
to be optional. If I have to specify it (even as an empty file) then
that's not very optional.

The manual says "If DEJAGNU is set, but the file cannot be located, an
error will be raised and runtest will abort." That makes sense, if I
name a file that doesn't exist, I'm doing something wrong. But if I
don't name any file, maybe that's because I don't want to use one. Why
warn me about the default behaviour?

This just adds confusion for new users of DejaGnu-based testsuites.