cmd/vet: `GO111MODULE=off go test -count=1 cmd/vet` fails

[cuonglm]

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

$ go version
go version devel +9be2d46422 Fri May 17 06:01:17 2019 +0000 linux/amd64

Does this issue reproduce with the latest release?

No

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/cuonglm/.cache/go-build"
GOENV="/home/cuonglm/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/cuonglm/go"
GOPROXY="direct"
GOROOT="/home/cuonglm/sources/go"
GOSUMDB="off"
GOTMPDIR=""
GOTOOLDIR="/home/cuonglm/sources/go/pkg/tool/linux_amd64"
GCCGO="/usr/local/bin/gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build714996541=/tmp/go-build -gno-record-gcc-switches"

What did you do?

$ GO111MODULE=off go vet cmd/vet/testdata/unsafeptr
$ GO111MODULE=on go vet cmd/vet/testdata/unsafeptr
# cmd/vet/testdata/unsafeptr
cmd/vet/testdata/unsafeptr/unsafeptr.go:12:6: possible misuse of unsafe.Pointer

What did you expect to see?

go vet produces output regardless of GO111MODULE value.

What did you see instead?

go vet does not produce output when GO111MODULE=off.

[cuonglm]

The culprit seems to be go.sum isn't updated. After run go mod tidy, then ./make.bash, test is now passed.

$ git diff
diff --git a/src/go.sum b/src/go.sum
index 4985320126..47f7f91435 100644
--- a/src/go.sum
+++ b/src/go.sum
@@ -1,17 +1,11 @@
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20190424203555-c05e17bb3b2d h1:adrbvkTDn9rGnXg2IJDKozEpXXLZN89pdIA+Syt4/u0=
-golang.org/x/crypto v0.0.0-20190424203555-c05e17bb3b2d/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f h1:R423Cnkcp5JABoeemiGEPlt9tHXFfw5kvc0yqlxRPWo=
 golang.org/x/crypto v0.0.0-20190513172903-22d7a77e9e5f/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190424112056-4829fb13d2c6 h1:FP8hkuE6yUEaJnK7O2eTuejKWwW+Rhfj80dQ2JcKxCU=
-golang.org/x/net v0.0.0-20190424112056-4829fb13d2c6/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190514140710-3ec191127204 h1:4yG6GqBtw9C+UrLp6s2wtSniayy/Vd/3F7ffLE427XI=
 golang.org/x/net v0.0.0-20190514140710-3ec191127204/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190425145619-16072639606e h1:4ktJgTV34+N3qOZUc5fAaG3Pb11qzMm3PkAoTAgUZ2I=
-golang.org/x/sys v0.0.0-20190425145619-16072639606e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190514135907-3a4b5fb9f71f h1:Xab8gg26GrI/x3RNdVhVkHHM1XLyGeRBEvz4Q5x4YW8=
 golang.org/x/sys v0.0.0-20190514135907-3a4b5fb9f71f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

[cuonglm]

Not sure why, the test now still pass even when I revert go.sum.

Anyway, do we have to update go.sum then? cc @bradfitz

If not, the issue can be closed.

[bcmills]

If the only changes are in go.sum, that shouldn't have any significant effect. Are you sure it's not the ./make.bash alone that fixed it?

[cuonglm]

@bcmills I think so. Here's the process:

• When the error happened, I have GO111MODULE=off when I work inside go git repo
• When I run go mod tidy, it complained about module is disabled.
• So I enable GO111MODULE=on
• Then run go mod tidy, then go did update something, and modify go.sum.
• I did go mod vendor, nothing change in vendor dir.
• ./make.bash, re-run the test, it passed.

[bcmills]

@rsc has been doing some refactoring in cmd/vet. Perhaps he knows?

[bradfitz]

https://build.golang.org/ looks happy, so this definitely seems like some local configuration problem.

[bcmills]

vet_test.go invokes vet using go vet -vettool=<test binary>:

go/src/cmd/vet/vet_test.go

Line 73 in ee55184

cmd := exec.Command(testenv.GoToolPath(t), "vet", "-vettool="+binary, arg, path.Join("cmd/vet/testdata", pkg))

Perhaps there has been a regression in the -vettool flag? The builders wouldn't detect that since they start with a fresh build every time.

(CC @jayconrod)

[cuonglm]

@bradfitz I think maybe because I set GO111MODULE=off

Hope anyone haven't run go mod tidy can try this.

[bcmills]

I really think go mod tidy is a red herring. It probably depends more on whatever version of cmd/vet you had built prior to re-running make.bash.

[cuonglm]

@bcmills @bradfitz Anyway, since when go mod tidy changes the go.sum, should I send a CL to update it?

[cuonglm]

@bcmills @bradfitz The error occurs again in my local

ok  	cmd/trace	0.064s
--- FAIL: TestVet (0.90s)
    --- FAIL: TestVet/print (0.27s)
        vet_test.go:162: error check failed: 
            print.go:169: missing error "Warn call has possible formatting directive %s"
            print.go:170: missing error "Warnf call needs 1 arg but has 2 args"
            print.go:171: missing error "Warnf format %r has unknown verb r"
            print.go:172: missing error "Warnf format %#s has unrecognized flag #"
            print.go:173: missing error "Warn2 call has possible formatting directive %s"
            print.go:174: missing error "Warnf2 call needs 1 arg but has 2 args"
            print.go:175: missing error "Warnf2 format %r has unknown verb r"
            print.go:176: missing error "Warnf2 format %#s has unrecognized flag #"
    --- FAIL: TestVet/unsafeptr (0.27s)
        vet_test.go:153: vet output:
        vet_test.go:154: <nil>
FAIL
FAIL	cmd/vet	1.939s
FAIL
2019/05/20 14:30:35 Failed: exit status 1