Re: ccache for MXE Octave cross builds

[John W. Eaton]

On 07/14/2018 09:16 AM, "Markus Mützel" wrote:
> Out of curiosity: How did you set up your ccache configuration for the Windows 
> cross-builds with MXE-Octave?
> My settings are:
> cat ~/.ccache/ccache.conf
> max_size = 30.0G
> hash_dir = false
>
> To me it looks like with these settings the compiler cache is only used for the "build-*" 
> packages after a "make clean".
> The later packages never seem to hit any cached files. Maybe because ccache 
> detects that the freshly built compiler is different from the previous run?
>
> Are there some settings or switches which allow the compiler cache to be used 
> more efficiently?

Did you use the --with-ccache option when configuring mxe-octave?

That is intended to cause the Makefile rules ot create links in 
usr/bin/ccache for the cross compiler that will be used, and also add 
usr/bin/ccache to the PATH that is used when make runs.  However, I now 
see that the ccache-links target in the Makefile will only be executed 
automatically if you execute make with the default "all" target. 
Otherwise, you need to execute "make ccache-links" explicitly.

I also see now that the usr/bin/ccache directory is not being created 
for the buildbots, so I don't think the cross-compile steps are taking 
advantage of ccache.  Oops.  I'll try to fix that so we get better 
performance for the mxe-octave builds.  That should speed things up a lot!

I don't use hash_dir = false.

I enabled logging to see what was being cached and found in the cache 
and it seems to work for me.

jwe