Gerrit: Reliability and fidelity of verification results

[Norbert Thiebaud]

On Mon, Jul 13, 2015 at 1:51 PM, David Ostrovsky <d.ostrovsky at gmx.de> wrote:
>> And your patch 8 would have failed the same way on tb58/tb59/tb60
>
> It requires a lot of efforts and time to upgrade all TBs to the newest
> baseline: 18 min. for OS + 22 min. for XCode. And we don't have time to
> do that. I understand all that.

Passive aggressive tone aside, for the record Yosemite + XCode download
is 7-8G... In the best of time that is 2-3 hours of download here...

>
> But what is the value of having conflicting tool chain versions
> verifying the Gerrit changes? So that change owners couldn't really
> trust the verification results, or if they do and submit changes that
> were approved by TB with up-to-date tool chain, they jeopardize green
> master or even stable release branch, because the same change is
> identified as breakage by a TB with stale tool chain?

The release builder have the so-called 'stale' tool chain.
Just like in real-life and like other platform there is a diversity of
platform and we usually do not drop
support for 'older' platform unless there is an imperative motivation.

Downgrading on Mac is not as trivial as you make it sound.. in fact
please explain to me how to do that
We've just put a brand new MacPro with Yosemite online, how would I go
about 'downgrading' it to maverick ?

Upgrading is 'easier' but not free.. and certainly not the 40 minutes
you say, otoh at some point we will upgrade...
But in the end your patch made a wrong assumption:
"There is no reason to use boost::bind when modern C++11 toolchain
is supported."
Apparently that support is not good enough for the supported baselines.
Do not get me wrong. I applaud the effort to get rid of boost if we
can.. that is a big and expensive dep.


>My suggestion is either to downgrade TB66 or upgrade all other Mac OS X
>TBs to the same baseline.

My suggestion is: adapt your patch to avoid the issue.
and/or bring the issue to the ESC. if dropping 10.9 is something that
people things is worth doing... I surely can upgrade my 10.9 mac...
although ti will take much more than 40 minutes to do so.

Norbert