hydra-eval-jobs: Transmit original Nix error when handling aggregate jobs

Dependencies

• [2] D4G756UK hydra-eval-jobs: Identify unexpected errors in handling aggregate jobs
• [3] VUYJ47EV hydra-eval-jobs: Parallelize
• [*] NQPGIRXX Revert "hydra-eval-jobs -> nix eval-hydra-jobs"

Change contents

• replacement in src/hydra-eval-jobs/hydra-eval-jobs.cc at line 470
  [2.1166]→[2.1166:1501](∅→∅)
  − auto drvPath2 = store->parseStorePath((std::string) (*job2)["drvPath"]);

  − auto drv2 = store->readDerivation(drvPath2);

  − job["constituents"].push_back(store->printStorePath(drvPath2));

  − drv.inputDrvs[drvPath2] = {drv2.outputs.begin()->first};
  [2.1166]

  [2.1501]
  +

  + if ((*job2).find("error") != (*job2).end()) {

  + if (job.find("error") == job.end()) {

  + job["error"] = fmt("Errors aggregating aggregate job '%1%'.\n", jobName);

  + }

  + job["error"] = fmt("While handling '%1%': %2%\n", jobName2, (std::string) (*job2)["error"]);

  + } else {

  + auto drvPath2 = store->parseStorePath((std::string) (*job2)["drvPath"]);

  + auto drv2 = store->readDerivation(drvPath2);

  + job["constituents"].push_back(store->printStorePath(drvPath2));

  + drv.inputDrvs[drvPath2] = {drv2.outputs.begin()->first};

  + }