[Scons-users] Need a better message when MSVC caching enabled

[Mats Wichmann]

On 1/31/20 8:58 PM, Eric Fahlgren wrote:
> So, I updated MSVC on a couple of machines today and all of a sudden I'm
> getting error messages about "cl not found".
> 
>>>> scons: Reading SConscript files ...
>>>>
>>>> scons: warning: Could not find MSVC compiler 'cl', it may need to be
> installed separately with Visual Studio
>>>> File "SConstruct", line 54, in __init__
> 
> I start digging in and the  path is pointing to the old version of the
> compiler, hmm where is this coming from?  A couple hours of hair pulling
> later I realize, oh $#!t, I've got SCONS_CACHE_MSVC_CONFIG turned on, so
> I delete ~/.scons_msvc_cache, voila, everything works fine.
> 
> Could we enhance the warning message to also say something like "if you
> have caching enabled, it may be out of date, see <path-to-cache-file>"
> or something like that?
> 
> I personally will never forget this again 😬, but it might help someone
> else in the future.

I'll look at how to improve on it.  This was the reason the feature was
marked experimental, figured something would go awry somewhere.

"A couple hours ... later I realize... I've got SCONS_CACHE_MSVC_CONFIG
turned on"

Sorry about that - it kind of reinforces why SCons doesn't like to
depend on the setting of environment vars, it's not always clear who's
got what set up :)