On 10/29/2015 02:17 AM, Markus Armbruster wrote: > John Snow <js...@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. >> 2) Force off CCACHE_CPP2 during the ccache test to get a deterministic >> answer over whether or not we need to enable that feature later. >> >> Signed-off-by: John Snow <js...@redhat.com>
