[apparmor] [RFC] [patch] Makefile automatically fallback to USE_SYSTEM=1

[Christian Boltz]

Hello,

Am Freitag, 7. März 2014 schrieb John Johansen:
> So this is a patch I have been using for a while to get around having
> to specify USE_SYSTEM=1 every time I run the tests. Is it worth
> upstreaming and applying to the other Makefiles that currently can
> take USE_SYSTEM as a parameter
> 
> If USE_SYSTEM=1 is NOT specified
>   it tries to find a local build and if it can't find one, it sets
>   USE_SYSTEM=1 and issues a warning message
> If USE_SYSTEM=1 is specified
>   it only tries building against the system libraries

I understand why you like this behaviour, but I don't like it too much 
because it introduces some "surprising" behaviour. (And I doubt someone 
reads the warning if the test succeeds ;-)


Thinking about it - can you implement an additional condition like 
"file common/enable-auto-fallback-to-USE_SYSTEM exists" (or an 
environment variable you set in .bashrc, but a file sounds better)?

That would mean people have to actively opt-in to the automatical 
fallback by touch'ing the file once in their bzr checkout. This would 
fix the "surprise" part.

With the opt-in file added, the patch looks good to me.


Regards,

Christian Boltz
-- 
Mit Java [...] werden auch oft Libraries um Libraries mit Spucke und
Heftpflaster zusammengepappt und irgendwann fällt alles um.
[Markus Stumpf zu
http://blog.koehntopp.de/archives/3213-Architektur-heisst-umbauen.html]