nix flake add: Handle ~/.config/nix not existing

Fixes

  $ nix flake add fnord github:edolstra/fnord
  error: opening file '/home/eelco/.config/nix/registry.json': No such file or directory
This commit is contained in:
Eelco Dolstra 2019-03-26 12:48:57 +01:00
parent 42be60c6af
commit f9c7176a87

View file

@ -23,16 +23,20 @@ std::unique_ptr<FlakeRegistry> readRegistry(const Path & path)
{ {
auto registry = std::make_unique<FlakeRegistry>(); auto registry = std::make_unique<FlakeRegistry>();
auto json = nlohmann::json::parse(readFile(path)); try {
auto json = nlohmann::json::parse(readFile(path));
auto version = json.value("version", 0); auto version = json.value("version", 0);
if (version != 1) if (version != 1)
throw Error("flake registry '%s' has unsupported version %d", path, version); throw Error("flake registry '%s' has unsupported version %d", path, version);
auto flakes = json["flakes"]; auto flakes = json["flakes"];
for (auto i = flakes.begin(); i != flakes.end(); ++i) { for (auto i = flakes.begin(); i != flakes.end(); ++i) {
FlakeRegistry::Entry entry{FlakeRef(i->value("uri", ""))}; FlakeRegistry::Entry entry{FlakeRef(i->value("uri", ""))};
registry->entries.emplace(i.key(), entry); registry->entries.emplace(i.key(), entry);
}
} catch (SysError & e) {
if (e.errNo != ENOENT) throw;
} }
return registry; return registry;
@ -47,6 +51,7 @@ void writeRegistry(FlakeRegistry registry, Path path)
for (auto elem : registry.entries) { for (auto elem : registry.entries) {
json["flakes"][elem.first] = { {"uri", elem.second.ref.to_string()} }; json["flakes"][elem.first] = { {"uri", elem.second.ref.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. writeFile(path, json.dump(4)); // The '4' is the number of spaces used in the indentation in the json file.
} }