go/types: TestStdlib fails due failed import in vendored pprof

[ysmolski]

What version of Go are you using (go version)?

~/golang/src (master=) % go version
go version devel +6876447952 Sat May 12 16:26:36 2018 +0000 darwin/amd64

How to reproduce

/golang/src % go test go/types
--- FAIL: TestStdlib (6.66s)
	stdlib_test.go:223: /Users/thorn/golang/src/cmd/vendor/github.com/google/pprof/pprof.go:24:2: could not import github.com/chzyer/readline (can't find import: "github.com/chzyer/readline")
	stdlib_test.go:223: /Users/thorn/golang/src/cmd/vendor/github.com/google/pprof/pprof.go:79:18: invalid operation: r.rl (variable of type *invalid type) has no field or method Stderr
	stdlib_test.go:223: /Users/thorn/golang/src/cmd/vendor/github.com/google/pprof/pprof.go:69:18: invalid operation: r.rl (variable of type *invalid type) has no field or method Stderr
	stdlib_test.go:223: /Users/thorn/golang/src/cmd/vendor/github.com/google/pprof/pprof.go:58:7: invalid operation: r.rl (variable of type *invalid type) has no field or method SetPrompt
	stdlib_test.go:223: /Users/thorn/golang/src/cmd/vendor/github.com/google/pprof/pprof.go:59:14: invalid operation: r.rl (variable of type *invalid type) has no field or method Readline
FAIL
FAIL	go/types	7.313s

Introduced in 46047e6 by @hyangah
Library "github.com/chzyer/readline" is not installed on my system and not vendored as well.

[agnivade]

Wonder how the try-bots passed this.

[ysmolski]

Maybe this test is not run by try-bots?

% go test -short go/types
ok  	go/types	0.370s

[agnivade]

That's right. Try-bots just run -short tests if I am not mistaken.

[mvdan]

I was under the impression that Go's pprof vendor wouldn't use readline, so we wouldn't have to pull it in as a dependency. If so, this is hopefully just a mistake with an easy fix.

[hyangah]

We don't use the file, so we can delete it.

[mvdan]

We should come up with a strategy to keep this from happening again, though. Even if the go/types test gets run by the builders, it wouldn't be part of the trybots, so I'm sure that the file would get re-added sooner than later.

If we were using a dependency management tool, this would be trivial - it's a main package, so it should not be vendored. Perhaps a better short-term solution is to add src/cmd/vendor/github.com/google/pprof/*.go to some gitignore file.

[gopherbot]

Change https://golang.org/cl/113295 mentions this issue: cmd/vendor/.../pprof: delete pprof.go file

[hyangah]

Currently there is no formal procedure to update this, so I will just write a script for update.

[mvdan]

Do you mean that vendor.json has been getting updated manually? I assumed that it was done with a tool like govendor, but I failed to get that one to work properly.