lix/src/libexpr/flake/flake.cc
Eelco Dolstra aeb7148afd
Some effort to minimize flake dependencies
For example, if the top-level flake depends on
"nixpkgs/release-19.03", and one of its dependencies depends on
"nixpkgs", then the latter will be mapped to "nixpkgs/release-19.03",
rather than whatever the default branch of "nixpkgs" is. Thus you get
only one "nixpkgs" dependency rather than two.

This currently only works in a breadth-first way, so the other way
around (i.e. if the top-level flake depends on "nixpkgs", and a
dependency depends on "nixpkgs/release-19.03") still results in two
"nixpkgs" dependencies.
2019-09-18 23:59:45 +02:00

705 lines
25 KiB
C++

#include "flake.hh"
#include "lockfile.hh"
#include "primops.hh"
#include "eval-inline.hh"
#include "primops/fetchGit.hh"
#include "download.hh"
#include "args.hh"
#include <iostream>
#include <queue>
#include <regex>
#include <ctime>
#include <iomanip>
#include <nlohmann/json.hpp>
namespace nix {
using namespace flake;
namespace flake {
/* Read a registry. */
std::shared_ptr<FlakeRegistry> readRegistry(const Path & path)
{
auto registry = std::make_shared<FlakeRegistry>();
if (!pathExists(path))
return std::make_shared<FlakeRegistry>();
auto json = nlohmann::json::parse(readFile(path));
auto version = json.value("version", 0);
if (version != 1)
throw Error("flake registry '%s' has unsupported version %d", path, version);
auto flakes = json["flakes"];
for (auto i = flakes.begin(); i != flakes.end(); ++i)
registry->entries.emplace(i.key(), FlakeRef(i->value("uri", "")));
return registry;
}
/* Write a registry to a file. */
void writeRegistry(const FlakeRegistry & registry, const Path & path)
{
nlohmann::json json;
json["version"] = 1;
for (auto elem : registry.entries)
json["flakes"][elem.first.to_string()] = { {"uri", elem.second.to_string()} };
createDirs(dirOf(path));
writeFile(path, json.dump(4)); // The '4' is the number of spaces used in the indentation in the json file.
}
Path getUserRegistryPath()
{
return getHome() + "/.config/nix/registry.json";
}
std::shared_ptr<FlakeRegistry> getUserRegistry()
{
return readRegistry(getUserRegistryPath());
}
std::shared_ptr<FlakeRegistry> getFlagRegistry(RegistryOverrides registryOverrides)
{
auto flagRegistry = std::make_shared<FlakeRegistry>();
for (auto const & x : registryOverrides) {
flagRegistry->entries.insert_or_assign(FlakeRef(x.first), FlakeRef(x.second));
}
return flagRegistry;
}
static FlakeRef lookupFlake(EvalState & state, const FlakeRef & flakeRef, const Registries & registries,
std::vector<FlakeRef> pastSearches = {});
FlakeRef updateFlakeRef(EvalState & state, const FlakeRef & newRef, const Registries & registries, std::vector<FlakeRef> pastSearches)
{
std::string errorMsg = "found cycle in flake registries: ";
for (FlakeRef oldRef : pastSearches) {
errorMsg += oldRef.to_string();
if (oldRef == newRef)
throw Error(errorMsg);
errorMsg += " - ";
}
pastSearches.push_back(newRef);
return lookupFlake(state, newRef, registries, pastSearches);
}
static FlakeRef lookupFlake(EvalState & state, const FlakeRef & flakeRef, const Registries & registries,
std::vector<FlakeRef> pastSearches)
{
for (std::shared_ptr<FlakeRegistry> registry : registries) {
auto i = registry->entries.find(flakeRef);
if (i != registry->entries.end()) {
auto newRef = i->second;
return updateFlakeRef(state, newRef, registries, pastSearches);
}
auto j = registry->entries.find(flakeRef.baseRef());
if (j != registry->entries.end()) {
auto newRef = j->second;
newRef.ref = flakeRef.ref;
newRef.rev = flakeRef.rev;
newRef.subdir = flakeRef.subdir;
return updateFlakeRef(state, newRef, registries, pastSearches);
}
}
if (!flakeRef.isDirect())
throw Error("could not resolve flake reference '%s'", flakeRef);
return flakeRef;
}
/* If 'allowLookup' is true, then resolve 'flakeRef' using the
registries. */
static FlakeRef maybeLookupFlake(
EvalState & state,
const FlakeRef & flakeRef,
bool allowLookup)
{
if (!flakeRef.isDirect()) {
if (allowLookup)
return lookupFlake(state, flakeRef, state.getFlakeRegistries());
else
throw Error("'%s' is an indirect flake reference, but registry lookups are not allowed", flakeRef);
} else
return flakeRef;
}
typedef std::vector<std::pair<FlakeRef, FlakeRef>> RefMap;
static FlakeRef lookupInRefMap(
const RefMap & refMap,
const FlakeRef & flakeRef)
{
// FIXME: inefficient.
for (auto & i : refMap) {
if (flakeRef.contains(i.first)) {
debug("mapping '%s' to previously seen input '%s' -> '%s",
flakeRef, i.first, i.second);
return i.second;
}
}
return flakeRef;
}
static SourceInfo fetchFlake(EvalState & state, const FlakeRef & resolvedRef)
{
assert(resolvedRef.isDirect());
auto doGit = [&](const GitInfo & gitInfo) {
FlakeRef ref(resolvedRef.baseRef());
ref.ref = gitInfo.ref;
ref.rev = gitInfo.rev;
SourceInfo info(ref);
info.storePath = gitInfo.storePath;
info.revCount = gitInfo.revCount;
info.narHash = state.store->queryPathInfo(info.storePath)->narHash;
info.lastModified = gitInfo.lastModified;
return info;
};
// This only downloads only one revision of the repo, not the entire history.
if (auto refData = std::get_if<FlakeRef::IsGitHub>(&resolvedRef.data)) {
// FIXME: use regular /archive URLs instead? api.github.com
// might have stricter rate limits.
auto url = fmt("https://api.github.com/repos/%s/%s/tarball/%s",
refData->owner, refData->repo,
resolvedRef.rev ? resolvedRef.rev->to_string(Base16, false)
: resolvedRef.ref ? *resolvedRef.ref : "master");
std::string accessToken = settings.githubAccessToken.get();
if (accessToken != "")
url += "?access_token=" + accessToken;
CachedDownloadRequest request(url);
request.unpack = true;
request.name = "source";
request.ttl = resolvedRef.rev ? 1000000000 : settings.tarballTtl;
request.getLastModified = true;
auto result = getDownloader()->downloadCached(state.store, request);
if (!result.etag)
throw Error("did not receive an ETag header from '%s'", url);
if (result.etag->size() != 42 || (*result.etag)[0] != '"' || (*result.etag)[41] != '"')
throw Error("ETag header '%s' from '%s' is not a Git revision", *result.etag, url);
FlakeRef ref(resolvedRef.baseRef());
ref.rev = Hash(std::string(*result.etag, 1, result.etag->size() - 2), htSHA1);
SourceInfo info(ref);
info.storePath = result.storePath;
info.narHash = state.store->queryPathInfo(info.storePath)->narHash;
info.lastModified = result.lastModified;
return info;
}
// This downloads the entire git history
else if (auto refData = std::get_if<FlakeRef::IsGit>(&resolvedRef.data)) {
return doGit(exportGit(state.store, refData->uri, resolvedRef.ref, resolvedRef.rev, "source"));
}
else if (auto refData = std::get_if<FlakeRef::IsPath>(&resolvedRef.data)) {
if (!pathExists(refData->path + "/.git"))
throw Error("flake '%s' does not reference a Git repository", refData->path);
return doGit(exportGit(state.store, refData->path, {}, {}, "source"));
}
else abort();
}
static void expectType(EvalState & state, ValueType type,
Value & value, const Pos & pos)
{
if (value.type == tThunk && value.isTrivial())
state.forceValue(value, pos);
if (value.type != type)
throw Error("expected %s but got %s at %s",
showType(type), showType(value.type), pos);
}
static Flake getFlake(EvalState & state, const FlakeRef & originalRef,
bool allowLookup, RefMap & refMap)
{
auto flakeRef = lookupInRefMap(refMap,
maybeLookupFlake(state,
lookupInRefMap(refMap, originalRef), allowLookup));
SourceInfo sourceInfo = fetchFlake(state, flakeRef);
debug("got flake source '%s' with flakeref %s", sourceInfo.storePath, sourceInfo.resolvedRef.to_string());
FlakeRef resolvedRef = sourceInfo.resolvedRef;
refMap.push_back({originalRef, resolvedRef});
refMap.push_back({flakeRef, resolvedRef});
state.store->assertStorePath(sourceInfo.storePath);
if (state.allowedPaths)
state.allowedPaths->insert(state.store->toRealPath(sourceInfo.storePath));
// Guard against symlink attacks.
Path flakeFile = canonPath(sourceInfo.storePath + "/" + resolvedRef.subdir + "/flake.nix");
Path realFlakeFile = state.store->toRealPath(flakeFile);
if (!isInDir(realFlakeFile, state.store->toRealPath(sourceInfo.storePath)))
throw Error("'flake.nix' file of flake '%s' escapes from '%s'", resolvedRef, sourceInfo.storePath);
Flake flake(originalRef, sourceInfo);
if (!pathExists(realFlakeFile))
throw Error("source tree referenced by '%s' does not contain a '%s/flake.nix' file", resolvedRef, resolvedRef.subdir);
Value vInfo;
state.evalFile(realFlakeFile, vInfo, true); // FIXME: symlink attack
expectType(state, tAttrs, vInfo, Pos(state.symbols.create(realFlakeFile), 0, 0));
auto sEdition = state.symbols.create("edition");
auto sEpoch = state.symbols.create("epoch"); // FIXME: remove soon
auto edition = vInfo.attrs->get(sEdition);
if (!edition)
edition = vInfo.attrs->get(sEpoch);
if (edition) {
expectType(state, tInt, *(**edition).value, *(**edition).pos);
flake.edition = (**edition).value->integer;
if (flake.edition > 201909)
throw Error("flake '%s' requires unsupported edition %d; please upgrade Nix", flakeRef, flake.edition);
if (flake.edition < 201909)
throw Error("flake '%s' has illegal edition %d", flakeRef, flake.edition);
} else
throw Error("flake '%s' lacks attribute 'edition'", flakeRef);
if (auto description = vInfo.attrs->get(state.sDescription)) {
expectType(state, tString, *(**description).value, *(**description).pos);
flake.description = (**description).value->string.s;
}
auto sInputs = state.symbols.create("inputs");
auto sUri = state.symbols.create("uri");
auto sFlake = state.symbols.create("flake");
if (std::optional<Attr *> inputs = vInfo.attrs->get(sInputs)) {
expectType(state, tAttrs, *(**inputs).value, *(**inputs).pos);
for (Attr inputAttr : *(*(**inputs).value).attrs) {
expectType(state, tAttrs, *inputAttr.value, *inputAttr.pos);
FlakeInput input(FlakeRef(inputAttr.name));
for (Attr attr : *(inputAttr.value->attrs)) {
if (attr.name == sUri) {
expectType(state, tString, *attr.value, *attr.pos);
input.ref = std::string(attr.value->string.s);
} else if (attr.name == sFlake) {
expectType(state, tBool, *attr.value, *attr.pos);
input.isFlake = attr.value->boolean;
} else
throw Error("flake input '%s' has an unsupported attribute '%s', at %s",
inputAttr.name, attr.name, *attr.pos);
}
flake.inputs.emplace(inputAttr.name, input);
}
}
auto sOutputs = state.symbols.create("outputs");
if (auto outputs = vInfo.attrs->get(sOutputs)) {
expectType(state, tLambda, *(**outputs).value, *(**outputs).pos);
flake.vOutputs = (**outputs).value;
if (flake.vOutputs->lambda.fun->matchAttrs) {
for (auto & formal : flake.vOutputs->lambda.fun->formals->formals) {
if (formal.name != state.sSelf)
flake.inputs.emplace(formal.name, FlakeInput(FlakeRef(formal.name)));
}
}
} else
throw Error("flake '%s' lacks attribute 'outputs'", flakeRef);
for (auto & attr : *vInfo.attrs) {
if (attr.name != sEdition &&
attr.name != sEpoch &&
attr.name != state.sDescription &&
attr.name != sInputs &&
attr.name != sOutputs)
throw Error("flake '%s' has an unsupported attribute '%s', at %s",
flakeRef, attr.name, *attr.pos);
}
return flake;
}
Flake getFlake(EvalState & state, const FlakeRef & originalRef, bool allowLookup)
{
RefMap refMap;
return getFlake(state, originalRef, allowLookup, refMap);
}
static SourceInfo getNonFlake(EvalState & state, const FlakeRef & originalRef,
bool allowLookup, RefMap & refMap)
{
auto flakeRef = lookupInRefMap(refMap,
maybeLookupFlake(state,
lookupInRefMap(refMap, originalRef), allowLookup));
auto sourceInfo = fetchFlake(state, flakeRef);
debug("got non-flake source '%s' with flakeref %s", sourceInfo.storePath, sourceInfo.resolvedRef.to_string());
FlakeRef resolvedRef = sourceInfo.resolvedRef;
refMap.push_back({originalRef, resolvedRef});
refMap.push_back({flakeRef, resolvedRef});
state.store->assertStorePath(sourceInfo.storePath);
if (state.allowedPaths)
state.allowedPaths->insert(sourceInfo.storePath);
return sourceInfo;
}
bool allowedToWrite(HandleLockFile handle)
{
return handle == UpdateLockFile || handle == RecreateLockFile;
}
bool recreateLockFile(HandleLockFile handle)
{
return handle == RecreateLockFile || handle == UseNewLockFile;
}
bool allowedToUseRegistries(HandleLockFile handle, bool isTopRef)
{
if (handle == AllPure) return false;
else if (handle == TopRefUsesRegistries) return isTopRef;
else if (handle == UpdateLockFile) return true;
else if (handle == UseUpdatedLockFile) return true;
else if (handle == RecreateLockFile) return true;
else if (handle == UseNewLockFile) return true;
else assert(false);
}
/* Given a flakeref and its subtree of the lockfile, return an updated
subtree of the lockfile. That is, if the 'flake.nix' of the
referenced flake has inputs that don't have a corresponding entry
in the lockfile, they're added to the lockfile; conversely, any
lockfile entries that don't have a corresponding entry in flake.nix
are removed.
Note that this is lazy: we only recursively fetch inputs that are
not in the lockfile yet. */
static std::pair<Flake, LockedInput> updateLocks(
RefMap & refMap,
const std::string & inputPath,
EvalState & state,
const Flake & flake,
HandleLockFile handleLockFile,
const LockedInputs & oldEntry,
bool topRef)
{
LockedInput newEntry(
flake.sourceInfo.resolvedRef,
flake.originalRef,
flake.sourceInfo.narHash);
std::vector<std::function<void()>> postponed;
for (auto & [id, input] : flake.inputs) {
auto inputPath2 = (inputPath.empty() ? "" : inputPath + "/") + id;
auto i = oldEntry.inputs.find(id);
if (i != oldEntry.inputs.end() && i->second.originalRef == input.ref) {
newEntry.inputs.insert_or_assign(id, i->second);
} else {
if (handleLockFile == AllPure || handleLockFile == TopRefUsesRegistries)
throw Error("cannot update flake input '%s' in pure mode", id);
auto warn = [&](const SourceInfo & sourceInfo) {
if (i == oldEntry.inputs.end())
printInfo("mapped flake input '%s' to '%s'",
inputPath2, sourceInfo.resolvedRef);
else
printMsg(lvlWarn, "updated flake input '%s' from '%s' to '%s'",
inputPath2, i->second.originalRef, sourceInfo.resolvedRef);
};
if (input.isFlake) {
auto actualInput = getFlake(state, input.ref,
allowedToUseRegistries(handleLockFile, false), refMap);
warn(actualInput.sourceInfo);
postponed.push_back([&, id{id}, inputPath2, actualInput]() {
newEntry.inputs.insert_or_assign(id,
updateLocks(refMap, inputPath2, state, actualInput, handleLockFile, {}, false).second);
});
} else {
auto sourceInfo = getNonFlake(state, input.ref,
allowedToUseRegistries(handleLockFile, false), refMap);
warn(sourceInfo);
newEntry.inputs.insert_or_assign(id,
LockedInput(sourceInfo.resolvedRef, input.ref, sourceInfo.narHash));
}
}
}
for (auto & f : postponed) f();
return {flake, newEntry};
}
/* Compute an in-memory lockfile for the specified top-level flake,
and optionally write it to file, it the flake is writable. */
ResolvedFlake resolveFlake(EvalState & state, const FlakeRef & topRef, HandleLockFile handleLockFile)
{
auto flake = getFlake(state, topRef,
allowedToUseRegistries(handleLockFile, true));
LockFile oldLockFile;
if (!recreateLockFile(handleLockFile)) {
// If recreateLockFile, start with an empty lockfile
// FIXME: symlink attack
oldLockFile = LockFile::read(
state.store->toRealPath(flake.sourceInfo.storePath)
+ "/" + flake.sourceInfo.resolvedRef.subdir + "/flake.lock");
}
RefMap refMap;
LockFile lockFile(updateLocks(
refMap, "", state, flake, handleLockFile, oldLockFile, true).second);
if (!(lockFile == oldLockFile)) {
if (allowedToWrite(handleLockFile)) {
if (auto refData = std::get_if<FlakeRef::IsPath>(&topRef.data)) {
if (lockFile.isDirty())
warn("will not write lock file of flake '%s' because it has a dirty input", topRef);
else {
lockFile.write(refData->path + (topRef.subdir == "" ? "" : "/" + topRef.subdir) + "/flake.lock");
// Hack: Make sure that flake.lock is visible to Git, so it ends up in the Nix store.
runProgram("git", true,
{ "-C", refData->path, "add",
"--force",
"--intent-to-add",
(topRef.subdir == "" ? "" : topRef.subdir + "/") + "flake.lock" });
}
} else
warn("cannot write lock file of remote flake '%s'", topRef);
} else if (handleLockFile != AllPure && handleLockFile != TopRefUsesRegistries)
warn("using updated lock file without writing it to file");
}
return ResolvedFlake(std::move(flake), std::move(lockFile));
}
void updateLockFile(EvalState & state, const FlakeRef & flakeRef, bool recreateLockFile)
{
resolveFlake(state, flakeRef, recreateLockFile ? RecreateLockFile : UpdateLockFile);
}
static void emitSourceInfoAttrs(EvalState & state, const SourceInfo & sourceInfo, Value & vAttrs)
{
auto & path = sourceInfo.storePath;
assert(state.store->isValidPath(path));
mkString(*state.allocAttr(vAttrs, state.sOutPath), path, {path});
if (sourceInfo.resolvedRef.rev) {
mkString(*state.allocAttr(vAttrs, state.symbols.create("rev")),
sourceInfo.resolvedRef.rev->gitRev());
mkString(*state.allocAttr(vAttrs, state.symbols.create("shortRev")),
sourceInfo.resolvedRef.rev->gitShortRev());
}
if (sourceInfo.revCount)
mkInt(*state.allocAttr(vAttrs, state.symbols.create("revCount")), *sourceInfo.revCount);
if (sourceInfo.lastModified)
mkString(*state.allocAttr(vAttrs, state.symbols.create("lastModified")),
fmt("%s",
std::put_time(std::gmtime(&*sourceInfo.lastModified), "%Y%m%d%H%M%S")));
}
struct LazyInput
{
bool isFlake;
LockedInput lockedInput;
};
/* Helper primop to make callFlake (below) fetch/call its inputs
lazily. Note that this primop cannot be called by user code since
it doesn't appear in 'builtins'. */
static void prim_callFlake(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
auto lazyInput = (LazyInput *) args[0]->attrs;
assert(lazyInput->lockedInput.ref.isImmutable());
if (lazyInput->isFlake) {
auto flake = getFlake(state, lazyInput->lockedInput.ref, false);
if (flake.sourceInfo.narHash != lazyInput->lockedInput.narHash)
throw Error("the content hash of flake '%s' doesn't match the hash recorded in the referring lockfile", flake.sourceInfo.resolvedRef);
callFlake(state, flake, lazyInput->lockedInput, v);
} else {
RefMap refMap;
auto sourceInfo = getNonFlake(state, lazyInput->lockedInput.ref, false, refMap);
if (sourceInfo.narHash != lazyInput->lockedInput.narHash)
throw Error("the content hash of repository '%s' doesn't match the hash recorded in the referring lockfile", sourceInfo.resolvedRef);
state.mkAttrs(v, 8);
assert(state.store->isValidPath(sourceInfo.storePath));
mkString(*state.allocAttr(v, state.sOutPath),
sourceInfo.storePath, {sourceInfo.storePath});
emitSourceInfoAttrs(state, sourceInfo, v);
}
}
void callFlake(EvalState & state,
const Flake & flake,
const LockedInputs & lockedInputs,
Value & vRes)
{
auto & vInputs = *state.allocValue();
state.mkAttrs(vInputs, flake.inputs.size() + 1);
for (auto & [inputId, input] : flake.inputs) {
auto vFlake = state.allocAttr(vInputs, inputId);
auto vPrimOp = state.allocValue();
static auto primOp = new PrimOp(prim_callFlake, 1, state.symbols.create("callFlake"));
vPrimOp->type = tPrimOp;
vPrimOp->primOp = primOp;
auto vArg = state.allocValue();
vArg->type = tNull;
auto lockedInput = lockedInputs.inputs.find(inputId);
assert(lockedInput != lockedInputs.inputs.end());
// FIXME: leak
vArg->attrs = (Bindings *) new LazyInput{input.isFlake, lockedInput->second};
mkApp(*vFlake, *vPrimOp, *vArg);
}
auto & vSourceInfo = *state.allocValue();
state.mkAttrs(vSourceInfo, 8);
emitSourceInfoAttrs(state, flake.sourceInfo, vSourceInfo);
vSourceInfo.attrs->sort();
vInputs.attrs->push_back(Attr(state.sSelf, &vRes));
vInputs.attrs->sort();
/* For convenience, put the outputs directly in the result, so you
can refer to an output of an input as 'inputs.foo.bar' rather
than 'inputs.foo.outputs.bar'. */
auto vCall = *state.allocValue();
state.eval(state.parseExprFromString(
"outputsFun: inputs: sourceInfo: let outputs = outputsFun inputs; in "
"outputs // sourceInfo // { inherit inputs; inherit outputs; inherit sourceInfo; }", "/"), vCall);
auto vCall2 = *state.allocValue();
auto vCall3 = *state.allocValue();
state.callFunction(vCall, *flake.vOutputs, vCall2, noPos);
state.callFunction(vCall2, vInputs, vCall3, noPos);
state.callFunction(vCall3, vSourceInfo, vRes, noPos);
}
void callFlake(EvalState & state,
const ResolvedFlake & resFlake,
Value & v)
{
callFlake(state, resFlake.flake, resFlake.lockFile, v);
}
// This function is exposed to be used in nix files.
static void prim_getFlake(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
callFlake(state, resolveFlake(state, state.forceStringNoCtx(*args[0], pos),
evalSettings.pureEval ? AllPure : UseUpdatedLockFile), v);
}
static RegisterPrimOp r2("getFlake", 1, prim_getFlake);
void gitCloneFlake(FlakeRef flakeRef, EvalState & state, Registries registries, const Path & destDir)
{
flakeRef = lookupFlake(state, flakeRef, registries);
std::string uri;
Strings args = {"clone"};
if (auto refData = std::get_if<FlakeRef::IsGitHub>(&flakeRef.data)) {
uri = "git@github.com:" + refData->owner + "/" + refData->repo + ".git";
args.push_back(uri);
if (flakeRef.ref) {
args.push_back("--branch");
args.push_back(*flakeRef.ref);
}
} else if (auto refData = std::get_if<FlakeRef::IsGit>(&flakeRef.data)) {
args.push_back(refData->uri);
if (flakeRef.ref) {
args.push_back("--branch");
args.push_back(*flakeRef.ref);
}
}
if (destDir != "")
args.push_back(destDir);
runProgram("git", true, args);
}
}
std::shared_ptr<flake::FlakeRegistry> EvalState::getGlobalFlakeRegistry()
{
std::call_once(_globalFlakeRegistryInit, [&]() {
auto path = evalSettings.flakeRegistry;
if (!hasPrefix(path, "/")) {
CachedDownloadRequest request(evalSettings.flakeRegistry);
request.name = "flake-registry.json";
request.gcRoot = true;
path = getDownloader()->downloadCached(store, request).path;
}
_globalFlakeRegistry = readRegistry(path);
});
return _globalFlakeRegistry;
}
// This always returns a vector with flakeReg, userReg, globalReg.
// If one of them doesn't exist, the registry is left empty but does exist.
const Registries EvalState::getFlakeRegistries()
{
Registries registries;
registries.push_back(getFlagRegistry(registryOverrides));
registries.push_back(getUserRegistry());
registries.push_back(getGlobalFlakeRegistry());
return registries;
}
Fingerprint ResolvedFlake::getFingerprint() const
{
// FIXME: as an optimization, if the flake contains a lock file
// and we haven't changed it, then it's sufficient to use
// flake.sourceInfo.storePath for the fingerprint.
return hashString(htSHA256,
fmt("%s;%s", flake.sourceInfo.storePath, lockFile));
}
}