From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48776) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtGVj-0003Sp-8p for qemu-devel@nongnu.org; Mon, 02 Nov 2015 09:55:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZtGVe-0005q0-9j for qemu-devel@nongnu.org; Mon, 02 Nov 2015 09:55:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33654) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZtGVe-0005pu-3h for qemu-devel@nongnu.org; Mon, 02 Nov 2015 09:54:58 -0500 References: <1446055000-29150-1-git-send-email-jsnow@redhat.com> <87611q8agw.fsf@blackfin.pond.sub.org> <563240ED.2080700@redhat.com> <87r3kdwsoa.fsf@blackfin.pond.sub.org> From: Paolo Bonzini Message-ID: <5637793D.1050307@redhat.com> Date: Mon, 2 Nov 2015 15:54:53 +0100 MIME-Version: 1.0 In-Reply-To: <87r3kdwsoa.fsf@blackfin.pond.sub.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] configure: disallow ccache during compile tests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster , John Snow Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org On 29/10/2015 17:22, Markus Armbruster wrote: > John Snow writes: > >> On 10/29/2015 02:17 AM, Markus Armbruster wrote: >>> John Snow 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