panic: http: multiple registrations for /debug/requests

Question

I vendored two projects in my go project. And I successfully compiled my project. When I ran my project, it reported error "panic: http: multiple registrations for /debug/requests". The detailed errors is shown below.

goroutine 1 [running]:
net/http.(*ServeMux).Handle(0x19ae000, 0x126bb20, 0xf, 0x1964540, 0x1297d90)
/usr/local/go/src/net/http/server.go:2270 +0x627
net/http.(*ServeMux).HandleFunc(0x19ae000, 0x126bb20, 0xf, 0x1297d90)
/usr/local/go/src/net/http/server.go:2302 +0x55
net/http.HandleFunc(0x126bb20, 0xf, 0x1297d90)
/usr/local/go/src/net/http/server.go:2314 +0x4b
github.own.com/chalex/testfabric/vendor/github.com/hyperledger/fabric-sdk-go/vendor/golang.org/x/net/trace.init.0()
/home/chalex/ibm/src/github.own.com/chalex/testfabric/vendor/github.com/hyperledger/fabric-sdk-go/vendor/golang.org/x/net/trace/trace.go:115 +0x42
github.own.com/chalex/testfabric/vendor/github.com/hyperledger/fabric-sdk-go/vendor/golang.org/x/net/trace.init()
<autogenerated>:1 +0x1cd
github.own.com/chalex/testfabric/vendor/github.com/hyperledger/fabric-sdk-go/vendor/google.golang.org/grpc.init()
<autogenerated>:1 +0x82
github.own.com/chalex/testfabric/vendor/github.com/hyperledger/fabric-sdk-go/third_party/github.com/hyperledger/fabric/protos/peer.init()
<autogenerated>:1 +0x6f
github.own.com/chalex/testfabric/vendor/github.com/hyperledger/fabric-sdk-go/api/apitxn.init()
<autogenerated>:1 +0x44
github.own.com/chalex/testfabric/chaincode/client.init()
<autogenerated>:1 +0x49
main.init()

Does anyone have any idea on how to fix it? I guess it's because the two projects I imported both listen on /debug/requests?

Brazilein

Your guess i right. Must change code. – Hildegard

This is why it's dangerous for libraries to do this sort of thing in init functions. They should only register handlers when you explicitly tell them to. – Anthrax

Thank you. @Hildegard @Adrian. I found the reason. It's because of the golang.org/x/net/trace project. In it's init() function, they handle the debug/request with hard code. So if two projects both import that library, then there is a conflict. – Brazilein

Answer 1

I found the reason. It's because of the golang.org/x/net/trace project. In it's init() function, they handle the debug/request with hard code. So if two projects both import that library, then there is a conflict.

Brazilein

The cause of issue is as explained by @chalex above. The temporary fix for me was to comment out the init() method inside the $GOPATH/pkg/mod/<mypackage>/Godeps/_/x/net/trace/trace.go – Berkeleianism

Answer 2

More than one project used golang.org/x/net/trace, and some project saved golang.org/x/net/trace in its vendor directory, so that is causing the conflict. Fix the conflict by deleting others and only leaving one,then the problem will be solved.

Pigeonhole

Does anyone know a way to figure out WHAT package is responsible for the "double" vendoring? – Gujarat