| what I've found is it is checking to see if the destStore (an S3BinaryCacheStoreImpl) has it as a valid path:
State::createStep (this=0x7fffffff7280, destStore=..., conn=..., build=std::shared_ptr<Build> (use count 5, weak count 1) = {...}, drvPath=..., referringBuild=std::shared_ptr<Build> (empty) = {...},
referringStep=std::shared_ptr<Step> (use count 2, weak count 2) = {...}, finishedDrvs=std::set with 1 element = {...}, newSteps=std::set with 0 elements, newRunnable=std::set with 0 elements)
at queue-monitor.cc:470
470 if (!destStore->isValidPath(*i.second.path(*localStore, step->drv->name, i.first))) {
isValidPath checks the disk cache:
428 if (diskCache) {
429 auto res = diskCache->lookupNarInfo(getUri(), hashPart);
430 if (res.first != NarInfoDiskCache::oUnknown) {
it doesn't know (oUnknown) and falls through to:
439 bool valid = isValidPathUncached(storePath);
440
441 if (diskCache && !valid)
442 // FIXME: handle valid = true case.
443 diskCache->upsertNarInfo(getUri(), hashPart, 0);
444
445 return valid;
and it does exist which ends up returning valid (true) here, with that FIXME hint.
from there we're back in the queue monitor:
470 if (!destStore->isValidPath(*i.second.path(*localStore, step->drv->name, i.first))) {
471 valid = false;
472 missing.insert_or_assign(i.first, i.second);
473 }
except the path is valid on the remote end despite not being on the local machine, so it never gets put in to "missing", so it never enters this:
475 /* Try to copy the missing paths from the local store or from
476 substitutes. */
477 if (!missing.empty()) {
at which point Hydra thinks it is ready to build a derivation where a dependent derivation's outputs are not available
| 
@grahamc:nixos.org
cransom
ajs124
andi-
vcunat