readLockfile = () => {
							intermediateFs.readFile(lockfileLocation, (err, buffer) => {
								if (err && err.code !== "ENOENT") {
									compilation.missingDependencies.add(lockfileLocation);
									return callback(err);
								}
								compilation.fileDependencies.add(lockfileLocation);
								compilation.fileSystemInfo.createSnapshot(
									compiler.fsStartTime,
									buffer ? [lockfileLocation] : [],
									[],
									buffer ? [] : [lockfileLocation],
									{ timestamp: true },
									(err, s) => {
										if (err) return callback(err);
										const lockfile = buffer
											? Lockfile.parse(buffer.toString("utf-8"))
											: new Lockfile();
										lockfileCache = {
											lockfile,
											snapshot: /** @type {Snapshot} */ (s)
										};
										callback(null, lockfile);
									}
								);
							});
						}
@param {(err: Error | null, lockfile?: Lockfile) => void} callback callback
@returns {void}