run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2021 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 // Targets runner
  19
  20 package main
  21
  22 import (
  23         "bufio"
  24         "errors"
  25         "flag"
  26         "fmt"
  27         "io"
  28         "os"
  29         "os/exec"
  30         "path"
  31         "path/filepath"
  32         "strconv"
  33         "strings"
  34         "sync"
  35         "syscall"
  36         "time"
  37
  38         "go.cypherpunks.ru/recfile"
  39         "go.cypherpunks.ru/tai64n/v2"
  40         "golang.org/x/sys/unix"
  41 )
  42
  43 const (
  44         EnvDepFd        = "REDO_DEP_FD"
  45         EnvDirPrefix    = "REDO_DIRPREFIX"
  46         EnvDepCwd       = "REDO_DEP_CWD"
  47         EnvBuildUUID    = "REDO_BUILD_UUID"
  48         EnvStderrPrefix = "REDO_STDERR_PREFIX"
  49         EnvTrace        = "REDO_TRACE"
  50         EnvStderrKeep   = "REDO_LOGS"
  51         EnvStderrSilent = "REDO_SILENT"
  52         EnvNoSync       = "REDO_NO_SYNC"
  53
  54         RedoDir    = ".redo"
  55         LockSuffix = ".lock"
  56         DepSuffix  = ".rec"
  57         TmpPrefix  = ".redo."
  58         LogSuffix  = ".log"
  59 )
  60
  61 var (
  62         NoSync       bool = false
  63         StderrKeep   bool = false
  64         StderrSilent bool = false
  65         StderrPrefix string
  66         Jobs         sync.WaitGroup
  67
  68         flagTrace        *bool
  69         flagTraceAll     *bool
  70         flagStderrKeep   *bool
  71         flagStderrSilent *bool
  72
  73         TracedAll bool
  74 )
  75
  76 func init() {
  77         cmdName := CmdName()
  78         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  79                 return
  80         }
  81         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  82         flagTraceAll = flag.Bool("xx", false,
  83                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  84         flagStderrKeep = flag.Bool("k", false,
  85                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  86         flagStderrSilent = flag.Bool("s", false,
  87                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
  88 }
  89
  90 type RunErr struct {
  91         Tgt      string
  92         DoFile   string
  93         Started  *time.Time
  94         Finished *time.Time
  95         Err      error
  96 }
  97
  98 func (e *RunErr) Name() string {
  99         var name string
 100         if e.DoFile == "" {
 101                 name = e.Tgt
 102         } else {
 103                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 104         }
 105         if e.Finished == nil {
 106                 return name
 107         }
 108         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 109 }
 110
 111 func (e RunErr) Error() string {
 112         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 113 }
 114
 115 func mkdirs(pth string) error {
 116         if _, err := os.Stat(pth); err == nil {
 117                 return nil
 118         }
 119         return os.MkdirAll(pth, os.FileMode(0777))
 120 }
 121
 122 func isModified(cwd, redoDir, tgt string) (bool, *Inode, error) {
 123         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 124         if err != nil {
 125                 if os.IsNotExist(err) {
 126                         return false, nil, nil
 127                 }
 128                 return false, nil, err
 129         }
 130         defer fdDep.Close()
 131         r := recfile.NewReader(fdDep)
 132         var ourInode *Inode
 133         for {
 134                 m, err := r.NextMap()
 135                 if err != nil {
 136                         if err == io.EOF {
 137                                 break
 138                         }
 139                         return false, nil, err
 140                 }
 141                 if m["Target"] != tgt {
 142                         continue
 143                 }
 144                 fd, err := os.Open(path.Join(cwd, tgt))
 145                 if err != nil {
 146                         if os.IsNotExist(err) {
 147                                 return false, nil, nil
 148                         }
 149                         return false, nil, err
 150                 }
 151                 ourInode, err = inodeFromFile(fd)
 152                 fd.Close()
 153                 if err != nil {
 154                         return false, nil, err
 155                 }
 156                 theirInode, err := inodeFromRec(m)
 157                 if err != nil {
 158                         return false, nil, err
 159                 }
 160                 if !ourInode.Equals(theirInode) {
 161                         return true, ourInode, nil
 162                 }
 163                 break
 164         }
 165         return false, ourInode, nil
 166 }
 167
 168 func syncDir(dir string) error {
 169         fd, err := os.Open(dir)
 170         if err != nil {
 171                 return err
 172         }
 173         err = fd.Sync()
 174         fd.Close()
 175         return err
 176 }
 177
 178 func runScript(tgtOrig string, errs chan error, traced bool) error {
 179         cwd, tgt := cwdAndTgt(tgtOrig)
 180         redoDir := path.Join(cwd, RedoDir)
 181         if err := mkdirs(redoDir); err != nil {
 182                 return TgtErr{tgtOrig, err}
 183         }
 184
 185         // Acquire lock
 186         fdLock, err := os.OpenFile(
 187                 path.Join(redoDir, tgt+LockSuffix),
 188                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 189                 os.FileMode(0666),
 190         )
 191         if err != nil {
 192                 return TgtErr{tgtOrig, err}
 193         }
 194         lockRelease := func() {
 195                 trace(CLock, "LOCK_UN: %s", fdLock.Name())
 196                 unix.Flock(int(fdLock.Fd()), unix.LOCK_UN)
 197                 fdLock.Close()
 198         }
 199         trace(CLock, "LOCK_NB: %s", fdLock.Name())
 200
 201         // Waiting for job completion, already taken by someone else
 202         if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
 203                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
 204                         fdLock.Close()
 205                         return TgtErr{tgtOrig, err}
 206                 }
 207                 Jobs.Add(1)
 208                 trace(CDebug, "waiting: %s", tgtOrig)
 209                 if FdStatus != nil {
 210                         FdStatus.Write([]byte{StatusWait})
 211                 }
 212                 go func() {
 213                         defer Jobs.Done()
 214                         trace(CLock, "LOCK_EX: %s", fdLock.Name())
 215                         unix.Flock(int(fdLock.Fd()), unix.LOCK_EX)
 216                         lockRelease()
 217                         trace(CDebug, "waiting done: %s", tgtOrig)
 218                         if FdStatus != nil {
 219                                 FdStatus.Write([]byte{StatusWaited})
 220                         }
 221                         var depInfo *DepInfo
 222                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 223                         if err != nil {
 224                                 if os.IsNotExist(err) {
 225                                         err = errors.New("was not built: no .rec")
 226                                 }
 227                                 goto Finish
 228                         }
 229                         defer fdDep.Close()
 230                         depInfo, err = depRead(fdDep)
 231                         if err != nil {
 232                                 goto Finish
 233                         }
 234                         if depInfo.build != BuildUUID {
 235                                 err = errors.New("was not built: build differs")
 236                         }
 237                 Finish:
 238                         if err != nil {
 239                                 err = TgtErr{tgtOrig, err}
 240                         }
 241                         errs <- err
 242                 }()
 243                 return nil
 244         }
 245
 246         // Check if target is not modified externally
 247         modified, inodePrev, err := isModified(cwd, redoDir, tgt)
 248         if err != nil {
 249                 lockRelease()
 250                 return TgtErr{tgtOrig, err}
 251         }
 252         if modified {
 253                 trace(CWarn, "%s externally modified: not redoing", tgtOrig)
 254                 lockRelease()
 255                 go func() {
 256                         errs <- nil
 257                 }()
 258                 return nil
 259         }
 260
 261         // Start preparing .rec
 262         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 263         if err != nil {
 264                 lockRelease()
 265                 return TgtErr{tgtOrig, err}
 266         }
 267         fdDepPath := fdDep.Name()
 268         cleanup := func() {
 269                 lockRelease()
 270                 fdDep.Close()
 271                 os.Remove(fdDep.Name())
 272         }
 273         if _, err = recfile.NewWriter(fdDep).WriteFields(
 274                 recfile.Field{Name: "Build", Value: BuildUUID},
 275         ); err != nil {
 276                 cleanup()
 277                 return TgtErr{tgtOrig, err}
 278         }
 279
 280         // Find .do
 281         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 282         if err != nil {
 283                 cleanup()
 284                 return TgtErr{tgtOrig, err}
 285         }
 286         if doFile == "" {
 287                 cleanup()
 288                 return TgtErr{tgtOrig, errors.New("no .do found")}
 289         }
 290
 291         // Determine basename and DIRPREFIX
 292         doFileRelPath := doFile
 293         ents := strings.Split(cwd, "/")
 294         ents = ents[len(ents)-upLevels:]
 295         dirPrefix := path.Join(ents...)
 296         cwdOrig := cwd
 297         for i := 0; i < upLevels; i++ {
 298                 cwd = path.Join(cwd, "..")
 299                 doFileRelPath = path.Join("..", doFileRelPath)
 300         }
 301         cwd = path.Clean(cwd)
 302         doFilePath := path.Join(cwd, doFile)
 303         basename := tgt
 304         runErr := RunErr{Tgt: tgtOrig}
 305         if strings.HasPrefix(doFile, "default.") {
 306                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 307                 runErr.DoFile = doFileRelPath
 308         }
 309
 310         if err = writeDep(fdDep, cwdOrig, doFileRelPath); err != nil {
 311                 cleanup()
 312                 return TgtErr{tgtOrig, err}
 313         }
 314         fdDep.Close()
 315         trace(CWait, "%s", runErr.Name())
 316
 317         // Prepare command line
 318         var cmdName string
 319         var args []string
 320         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 321                 cmdName = doFilePath
 322                 args = make([]string, 0, 3)
 323         } else {
 324                 cmdName = "/bin/sh"
 325                 if traced || TracedAll {
 326                         args = append(args, "-ex")
 327                 } else {
 328                         args = append(args, "-e")
 329                 }
 330                 args = append(args, doFile)
 331         }
 332
 333         // Temporary file for stdout
 334         fdStdout, err := tempfile(cwdOrig, tgt)
 335         if err != nil {
 336                 cleanup()
 337                 return TgtErr{tgtOrig, err}
 338         }
 339         stdoutPath := fdStdout.Name()
 340         fdStdout.Close()
 341         tmpPath := stdoutPath + ".3" // and for $3
 342         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 343         if err != nil {
 344                 panic(err)
 345         }
 346         args = append(
 347                 args,
 348                 path.Join(dirPrefix, tgt),
 349                 path.Join(dirPrefix, basename),
 350                 tmpPathRel,
 351         )
 352
 353         cmd := exec.Command(cmdName, args...)
 354         cmd.Dir = cwd
 355         // cmd.Stdin reads from /dev/null by default
 356         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 357         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 358         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 359
 360         childStderrPrefix := tempsuffix()
 361         cmd.Env = append(cmd.Env, fmt.Sprintf(
 362                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 363         ))
 364
 365         fdNum := 0
 366         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 367         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 368         fdNum++
 369         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 370         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 371         fdNum++
 372
 373         if FdStatus == nil {
 374                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 375         } else {
 376                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 377                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 378                 fdNum++
 379         }
 380
 381         // Preparing stderr
 382         var fdStderr *os.File
 383         if StderrKeep {
 384                 fdStderr, err = os.OpenFile(
 385                         path.Join(redoDir, tgt+LogSuffix),
 386                         os.O_WRONLY|os.O_CREATE,
 387                         os.FileMode(0666),
 388                 )
 389                 if err != nil {
 390                         cleanup()
 391                         return TgtErr{tgtOrig, err}
 392                 }
 393                 fdStderr.Truncate(0)
 394         }
 395         shCtx := fmt.Sprintf(
 396                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 397                 tgtOrig, cmdName, args, cwd, dirPrefix,
 398         )
 399         trace(CDebug, "%s", shCtx)
 400
 401         Jobs.Add(1)
 402         go func() {
 403                 jsToken := jsAcquire(shCtx)
 404                 if JSR == nil {
 405                         // infinite jobs
 406                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 407                 } else {
 408                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 409                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 410                         cmd.Env = append(cmd.Env, fmt.Sprintf(
 411                                 "%s=%s %s%d,%d",
 412                                 MakeFlagsName, MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 413                         ))
 414                         fdNum += 2
 415                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 416                 }
 417
 418                 if FdStatus != nil {
 419                         FdStatus.Write([]byte{StatusRun})
 420                 }
 421
 422                 var finished time.Time
 423                 var exitErr *exec.ExitError
 424                 started := time.Now()
 425                 runErr.Started = &started
 426                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 427                 if err != nil {
 428                         runErr.Err = err
 429                         errs <- runErr
 430                         return
 431                 }
 432                 cmd.Stdout = fdStdout
 433                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 434                 if err != nil {
 435                         runErr.Err = err
 436                         errs <- runErr
 437                         return
 438                 }
 439                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 440                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 441                 fdNum++
 442                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 443
 444                 defer func() {
 445                         jsRelease(shCtx, jsToken)
 446                         fdDep.Close()
 447                         fdStdout.Close()
 448                         if fdStderr != nil {
 449                                 fdStderr.Close()
 450                                 logRecPath := path.Join(redoDir, tgt+LogSuffix+DepSuffix)
 451                                 if fdStderr, err = os.OpenFile(
 452                                         logRecPath,
 453                                         os.O_WRONLY|os.O_CREATE,
 454                                         os.FileMode(0666),
 455                                 ); err == nil {
 456                                         fdStderr.Truncate(0)
 457                                         fields := []recfile.Field{
 458                                                 {Name: "Build", Value: BuildUUID},
 459                                                 {Name: "PID", Value: strconv.Itoa(cmd.Process.Pid)},
 460                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 461                                                 {Name: "Cwd", Value: cwd},
 462                                         }
 463                                         ts := new(tai64n.TAI64N)
 464                                         ts.FromTime(started)
 465                                         fields = append(fields,
 466                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 467                                         )
 468                                         ts.FromTime(finished)
 469                                         fields = append(fields,
 470                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 471                                         fields = append(fields, recfile.Field{
 472                                                 Name:  "Duration",
 473                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 474                                         })
 475                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 476                                         for _, arg := range args {
 477                                                 fields = append(fields, recfile.Field{Name: "Cmd", Value: arg})
 478                                         }
 479                                         for _, e := range cmd.Env {
 480                                                 fields = append(fields, recfile.Field{Name: "Env", Value: e})
 481                                         }
 482                                         if exitErr != nil {
 483                                                 fields = append(fields, recfile.Field{
 484                                                         Name:  "ExitCode",
 485                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 486                                                 })
 487                                         }
 488                                         w := bufio.NewWriter(fdStderr)
 489                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 490                                         w.Flush()
 491                                         fdStderr.Close()
 492                                         if err != nil {
 493                                                 os.Remove(logRecPath)
 494                                         }
 495                                 }
 496                         }
 497                         lockRelease()
 498                         os.Remove(fdDep.Name())
 499                         os.Remove(fdStdout.Name())
 500                         os.Remove(tmpPath)
 501                         os.Remove(fdLock.Name())
 502                         if FdStatus != nil {
 503                                 FdStatus.Write([]byte{StatusDone})
 504                         }
 505                         Jobs.Done()
 506                 }()
 507                 stderr, err := cmd.StderrPipe()
 508                 if err != nil {
 509                         runErr.Err = err
 510                         errs <- runErr
 511                         return
 512                 }
 513                 started = time.Now()
 514                 err = cmd.Start()
 515                 if err != nil {
 516                         runErr.Err = err
 517                         errs <- runErr
 518                         return
 519                 }
 520                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 521                 trace(CDebug, "%s runs %s", tgtOrig, pid)
 522
 523                 stderrTerm := make(chan struct{}, 0)
 524                 go func() {
 525                         scanner := bufio.NewScanner(stderr)
 526                         var line string
 527                         ts := new(tai64n.TAI64N)
 528                         for scanner.Scan() {
 529                                 line = scanner.Text()
 530                                 if strings.HasPrefix(line, childStderrPrefix) {
 531                                         line = line[len(childStderrPrefix):]
 532                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 533                                         continue
 534                                 }
 535                                 if fdStderr != nil {
 536                                         ts.FromTime(time.Now())
 537                                         LogMutex.Lock()
 538                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 539                                         LogMutex.Unlock()
 540                                 }
 541                                 if StderrSilent {
 542                                         continue
 543                                 }
 544                                 if MyPid == 0 {
 545                                         trace(CNone, "%s", line)
 546                                 } else {
 547                                         trace(CNone, "%s %s", pid, line)
 548                                 }
 549                         }
 550                         close(stderrTerm)
 551                 }()
 552
 553                 // Wait for job completion
 554                 <-stderrTerm
 555                 err = cmd.Wait()
 556                 finished = time.Now()
 557                 runErr.Finished = &finished
 558                 if err != nil {
 559                         // Try to commit .rec anyway
 560                         if !NoSync {
 561                                 fdDep.Sync()
 562                         }
 563                         os.Rename(fdDep.Name(), path.Join(redoDir, tgt+DepSuffix))
 564                         if !NoSync {
 565                                 err = syncDir(redoDir)
 566                         }
 567
 568                         exitErr = err.(*exec.ExitError)
 569                         runErr.Err = err
 570                         errs <- runErr
 571                         return
 572                 }
 573
 574                 // Was $1 touched?
 575                 if inodePrev != nil {
 576                         if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 577                                 inode, err := inodeFromFile(fd)
 578                                 fd.Close()
 579                                 if err == nil && !inode.Equals(inodePrev) {
 580                                         runErr.Err = errors.New("$1 was explicitly touched")
 581                                         errs <- runErr
 582                                         return
 583                                 }
 584                         }
 585                 }
 586
 587                 // Does it produce both stdout and tmp?
 588                 fiStdout, err := os.Stat(fdStdout.Name())
 589                 if err != nil {
 590                         runErr.Err = err
 591                         errs <- runErr
 592                         return
 593                 }
 594                 tmpExists := false
 595                 _, err = os.Stat(tmpPath)
 596                 if err == nil {
 597                         if fiStdout.Size() > 0 {
 598                                 runErr.Err = errors.New("created both tmp and stdout")
 599                                 errs <- runErr
 600                                 return
 601                         }
 602                         tmpExists = true
 603                 } else if !os.IsNotExist(err) {
 604                         runErr.Err = err
 605                         errs <- runErr
 606                         return
 607                 }
 608
 609                 // Determine what file we must process at last
 610                 var fd *os.File
 611                 if tmpExists {
 612                         fd, err = os.Open(tmpPath)
 613                         if err != nil {
 614                                 goto Finish
 615                         }
 616                         defer fd.Close()
 617                 } else if fiStdout.Size() > 0 {
 618                         fd = fdStdout
 619                 }
 620
 621                 // Do we need to ifcreate it, of ifchange with renaming?
 622                 if fd == nil {
 623                         os.Remove(path.Join(cwdOrig, tgt))
 624                         err = ifcreate(fdDep, tgt)
 625                         if err != nil {
 626                                 goto Finish
 627                         }
 628                 } else {
 629                         if !NoSync {
 630                                 err = fd.Sync()
 631                                 if err != nil {
 632                                         goto Finish
 633                                 }
 634                         }
 635                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 636                         if err != nil {
 637                                 goto Finish
 638                         }
 639                         if !NoSync {
 640                                 err = syncDir(cwdOrig)
 641                                 if err != nil {
 642                                         goto Finish
 643                                 }
 644                         }
 645                         err = writeDep(fdDep, cwdOrig, tgt)
 646                         if err != nil {
 647                                 goto Finish
 648                         }
 649                 }
 650
 651                 // Commit .rec
 652                 if !NoSync {
 653                         err = fdDep.Sync()
 654                         if err != nil {
 655                                 goto Finish
 656                         }
 657                 }
 658                 err = os.Rename(fdDep.Name(), path.Join(redoDir, tgt+DepSuffix))
 659                 if err != nil {
 660                         goto Finish
 661                 }
 662                 if !NoSync {
 663                         err = syncDir(redoDir)
 664                         if err != nil {
 665                                 goto Finish
 666                         }
 667                 }
 668         Finish:
 669                 runErr.Err = err
 670                 errs <- runErr
 671         }()
 672         return nil
 673 }
 674
 675 func isOkRun(err error) bool {
 676         if err == nil {
 677                 return true
 678         }
 679         if err, ok := err.(RunErr); ok && err.Err == nil {
 680                 trace(CRedo, "%s", err.Name())
 681                 return true
 682         }
 683         trace(CErr, "%s", err)
 684         return false
 685 }