Keep temporary directory in case of failure

Signed-off-by: Chris Koch <[email protected]>

cmd/mkuimage/main.go

@@ -18,6 +18,7 @@ import (
  "github.com/dustin/go-humanize"
  "github.com/u-root/gobusybox/src/pkg/golang"
  "github.com/u-root/mkuimage/uimage"
+ "github.com/u-root/mkuimage/uimage/builder"
  "github.com/u-root/mkuimage/uimage/uflags"
  "github.com/u-root/uio/llog"
 )
@@ -137,19 +138,20 @@ func Main(l *llog.Logger, env *golang.Environ, f *uflags.Flags) error {
  v, recommendedVersions, recommendedVersions[0])
  }
 
+ keepTempDir := f.KeepTempDir
  if f.TempDir == "" {
  var err error
  f.TempDir, err = os.MkdirTemp("", "u-root")
  if err != nil {
  return err
  }
- if f.KeepTempDir {
- defer func() {
+ defer func() {
+ if keepTempDir {
  l.Infof("Keeping temp dir %s", f.TempDir)
- }()
- } else {
- defer os.RemoveAll(f.TempDir)
- }
+ } else {
+  os.RemoveAll(f.TempDir)
+ }
+ }()
  } else if _, err := os.Stat(f.TempDir); os.IsNotExist(err) {
  if err := os.MkdirAll(f.TempDir, 0o755); err != nil {
  return fmt.Errorf("temporary directory %q did not exist; tried to mkdir but failed: %v", f.TempDir, err)
@@ -166,5 +168,11 @@ func Main(l *llog.Logger, env *golang.Environ, f *uflags.Flags) error {
  if err != nil {
  return err
  }
- return uimage.Create(l, append(m, more...)...)
+
+ err = uimage.Create(l, append(m, more...)...)
+ if errors.Is(err, builder.ErrBusyboxFailed) {
+ l.Errorf("Preserving temp dir due to busybox build error")
+ keepTempDir = true
+ }
+ return err
 }

uimage/builder/builder.go

@@ -24,6 +24,7 @@ var (
 
 // Possible build errors.
 var (
+ ErrBusyboxFailed = errors.New("gobusybox build failed")
  ErrEnvMissing = errors.New("must specify Go build environment")
  ErrTempDirMissing = errors.New("must supply temporary directory for build")
  ErrNoGoFiles = errors.New("could not find package directory")

uimage/builder/gbb.go

@@ -80,12 +80,12 @@ func (b *GBBBuilder) Build(l *llog.Logger, af *initramfs.Files, opts Opts) error
  var errGopath *bb.ErrGopathBuild
  var errGomod *bb.ErrModuleBuild
  if errors.As(err, &errGopath) {
- return fmt.Errorf("preserving bb generated source directory at %s due to error. To reproduce build, `cd %s` and `GO111MODULE=off GOPATH=%s go build`: %w", opts.TempDir, errGopath.CmdDir, errGopath.GOPATH, err)
+ return fmt.Errorf("%w: to reproduce build, `cd %s` and `GO111MODULE=off GOPATH=%s go build`: %w", ErrBusyboxFailed, errGopath.CmdDir, errGopath.GOPATH, err)
  }
  if errors.As(err, &errGomod) {
- return fmt.Errorf("preserving bb generated source directory at %s due to error. To debug build, `cd %s` and use `go build` to build, or `go mod [why|tidy|graph]` to debug dependencies, or `go list -m all` to list all dependency versions:\n%w", opts.TempDir, errGomod.CmdDir, err)
+ return fmt.Errorf("%w: to debug build, `cd %s` and use `go build` to build, or `go mod [why|tidy|graph]` to debug dependencies, or `go list -m all` to list all dependency versions:\n%w", ErrBusyboxFailed, errGomod.CmdDir, err)
  }
- return fmt.Errorf("preserving bb generated source directory at %s due to error:\n%w", opts.TempDir, err)
+ return fmt.Errorf("%w: %w", ErrBusyboxFailed, err)
  }
 
  if err := af.AddFile(bbPath, "bbin/bb"); err != nil {

uimage/uimage.go

@@ -647,7 +647,7 @@ func CreateInitramfs(l *llog.Logger, opts Opts) error {
  BinaryDir: cmds.TargetDir(),
  }
  if err := cmds.Builder.Build(l, files, bOpts); err != nil {
- return fmt.Errorf("error building: %v", err)
+ return fmt.Errorf("error building: %w", err)
  }
  }