Re: [Qemu-devel] [PATCH] configure: disallow ccache during compile tests

[Paolo Bonzini <pbonzini@redhat.com>]

On 29/10/2015 17:22, Markus Armbruster wrote:
> John Snow <jsnow@redhat.com> writes:
> 
>> On 10/29/2015 02:17 AM, Markus Armbruster wrote:
>>> John Snow <jsnow@redhat.com> writes:
>>>
>>>> If the user is using CCACHE during the configuration step,
>>>> it may interfere with some of the configuration tests,
>>>> particularly the "Is CCACHE interfering with macro analysis" step,
>>>> which is a bit of a poetic problem.
>>>>
>>>> 1) Disallow CCACHE from reading from the cache during configure,
>>>>    but don't disable it to allow us to see if it causes other problems.
>>>
>>> This is confusing.  "don't disable it entirely"?
>>>
>>
>> We allow it to submit items into the cache, but not to read items from
>> the cache. This prevents it from picking up cached results to the
>> compile tests.
>>
>> I don't disable it entirely (just pass-through to the real compiler
>> without using ccache at all) because I still want to allow ccache to be
>> processing things to test for ccache failures -- particularly the ccache
>> macro check that occurs later.
>>
>> If I just disable ccache, that later check is meaningless. Setting the
>> cache to "write only" gives me the best of both worlds.
> 
> All right, shows that I can confuse with the best of them!
> 
> It took my a moment to understand what "disallow but don't disable"
> means.  I think inserting "entirely" into your sentence right after
> "disable it" makes it easier to understand.

Ok, commit log adjusted.

Paolo