lix/src/libstore/build/substitution-goal.hh
Eelco Dolstra 318936366d Fix empty 'nix copy' error message
This was caused by SubstitutionGoal not setting the errorMsg field in
its BuildResult. We now get a more descriptive message than in 2.7.0, e.g.

  error: path '/nix/store/13mh...' is required, but there is no substituter that can build it

instead of the misleading (since there was no build)

  error: build of '/nix/store/13mh...' failed

Fixes #6295.
2022-04-06 12:43:53 +02:00

92 lines
2.4 KiB
C++

#pragma once
#include "lock.hh"
#include "store-api.hh"
#include "goal.hh"
namespace nix {
class Worker;
struct PathSubstitutionGoal : public Goal
{
/* The store path that should be realised through a substitute. */
StorePath storePath;
/* The path the substituter refers to the path as. This will be
different when the stores have different names. */
std::optional<StorePath> subPath;
/* The remaining substituters. */
std::list<ref<Store>> subs;
/* The current substituter. */
std::shared_ptr<Store> sub;
/* Whether a substituter failed. */
bool substituterFailed = false;
/* Path info returned by the substituter's query info operation. */
std::shared_ptr<const ValidPathInfo> info;
/* Pipe for the substituter's standard output. */
Pipe outPipe;
/* The substituter thread. */
std::thread thr;
std::promise<void> promise;
/* Whether to try to repair a valid path. */
RepairFlag repair;
/* Location where we're downloading the substitute. Differs from
storePath when doing a repair. */
Path destPath;
std::unique_ptr<MaintainCount<uint64_t>> maintainExpectedSubstitutions,
maintainRunningSubstitutions, maintainExpectedNar, maintainExpectedDownload;
typedef void (PathSubstitutionGoal::*GoalState)();
GoalState state;
/* Content address for recomputing store path */
std::optional<ContentAddress> ca;
void done(
ExitCode result,
BuildResult::Status status,
std::optional<std::string> errorMsg = {});
public:
PathSubstitutionGoal(const StorePath & storePath, Worker & worker, RepairFlag repair = NoRepair, std::optional<ContentAddress> ca = std::nullopt);
~PathSubstitutionGoal();
void timedOut(Error && ex) override { abort(); };
std::string key() override
{
/* "a$" ensures substitution goals happen before derivation
goals. */
return "a$" + std::string(storePath.name()) + "$" + worker.store.printStorePath(storePath);
}
void work() override;
/* The states. */
void init();
void tryNext();
void gotInfo();
void referencesValid();
void tryToRun();
void finished();
/* Callback used by the worker to write to the log. */
void handleChildOutput(int fd, std::string_view data) override;
void handleEOF(int fd) override;
void cleanup() override;
};
}