httpreplay: Get error "flag redefined: v" when trying to get new Recorder

[tomasbanet]

httpreplay version: v0.103.0

Code

_, err := httpreplay.NewRecorder("gcs-recorder-output.txt", []byte{})
if err != nil {
  return nil, err
}

Expected behavior

httpreplay.Recorder is instantiated without any errors.

Actual behavior

Got the following runtime error when trying to run the compiled binary:

panic: ./bin flag redefined: v

goroutine 1 [running]:
flag.(*FlagSet).Var(0xc00004e1e0, {0x22c1d40, 0xc0003294d8}, {0x22b2b69, 0x1}, {0x20dc402, 0x9})
	/usr/local/Cellar/go/1.18.2/libexec/src/flag/flag.go:879 +0x2f4
flag.(*FlagSet).IntVar(...)
	/usr/local/Cellar/go/1.18.2/libexec/src/flag/flag.go:658
flag.(*FlagSet).Int(0x8?, {0x22b2b69, 0x1}, 0x0, {0x20dc402, 0x9})
	/usr/local/Cellar/go/1.18.2/libexec/src/flag/flag.go:671 +0x7e
flag.Int(...)
	/usr/local/Cellar/go/1.18.2/libexec/src/flag/flag.go:678
github.com/google/martian/v3.init()
	/Users/tomasb/go/src/arista/vendor/github.com/google/martian/v3/init.go:24 +0x65

It looks like "github.com/google/martian/v3" is being imported twice. In vendor/cloud.google.com/go/httpreplay/internal/proxy/log.go and in vendor/cloud.google.com/go/httpreplay/internal/proxy/record.go. This causes the Init function from vendor/github.com/google/martian/v3/init.go to run:

var (
	level = flag.Int("v", 0, "log level")
)

// Init runs common initialization code for a martian proxy.
func Init() {
	flag.Parse()
	mlog.SetLevel(*level)
}

This seems to cause the flag parsing error.

As a work-around you can do:

// Init runs common initialization code for a martian proxy.
func Init() {
	level := flag.Int("v", 0, "log level")
	flag.Parse()
	mlog.SetLevel(*level)
}

which seems to run fine.

Go Environment

$ go version
go version go1.18.2 darwin/amd64

[codyoss]

Hey, thanks for the report. Quickly reading this I would say this is an issue in martian. It looks like you found a relevant issue too. Can this be closed out. I don't believe we have a v flag at all unless I am missing something.

[codyoss]

Closing due to lack of response.

[tomasbanet]

Hi. Sorry. Looks like martian maintainers merged a fix into master 10 days ago (it's in v3.3.2). Maybe we could bump up the github.com/google/martian/v3 dependency to this version? (currently it's v3.2.1)

[codyoss]

Sure, I can do that. You can always also explicitly require a higher version in your module to work around this. Just underscore import martian and depend on the latest.

[codyoss]

Until we drop support for Go 1.15 we can't upgrade this dep in our code. It use a symbol net.ErrClosed from 1.16 in its latest code. We will update once we have a min support version >=1.16

[tomasbanet]

Sure, I can do that. You can always also explicitly require a higher version in your module to work around this. Just underscore import martian and depend on the latest.

Good suggestion. Thanks