Hi, Mathieu Othacehe <othac...@gnu.org> skribis:
>> here is an example: https://ci.guix.gnu.org/build/287478/details and >> https://ci.guix.gnu.org/build/287476/details are being built at the >> same time, and the logs currently show they are both running the test >> phase of the php package. > > Thanks for the report. This problem has been briefly discussed > yesterday. It has been introduced by the new remote building mechanism > in Cuirass. Hydra solves it by breaking each build into buildsteps > corresponding to the derivation inputs. > > The buildsteps are then submitted to the workers in a logical order. I > proposed to introduce a similar mechanism in Cuirass but Ludo expressed > doubts. Ludo do you think this problem could be solved otherwise? I’m not sure exactly but I can share my feelings. :-) Seems to me that ‘BuildSteps’ is an orthogonal concern that has little to do with Cuirass’ job and with its data model. In Hydra I saw that as a (necessary) kludge. I like the way the Coordinator does it, and AIUI it’s pretty much the same as what the daemon is doing: submit build requests in topological order, such that when a derivation build is submitted, its prerequisites are known to be built already. I suppose what makes it more difficult here is that we have this extra “job” abstraction on top of derivations; everything in Cuirass revolves around jobs, which leads to this impedance mismatch. If Cuirass would instead delegate derivation build requests to a Coordinator/daemon-like thing, it wouldn’t have to worry about those details. That would better separate concerns. This is quite a hand-wavy reply but I hope it’s useful! Thanks, Ludo’.
