cmd/go: test gets hung #27720

alecthomas · 2018-09-18T01:05:28Z

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

go version go1.11 darwin/amd64

Does this issue reproduce with the latest release?

Yes

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

GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/aat/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/aat/.go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/go1.11"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go1.11/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/aat/Downloads/gap/go.mod"
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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/db/mz_hvw_x54q6mcrbgmslnq7400042q/T/go-build995577183=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

[aat@cavern:~/Downloads/gap]go test -x -v ./...
^\SIGQUIT: quit
PC=0x7fff5606ccee m=0 sigcode=0

goroutine 0 [idle]:
runtime.pthread_cond_wait(0x1961440, 0x1961400, 0x7ffe00000000)
	/usr/local/go/src/runtime/sys_darwin.go:302 +0x51
runtime.semasleep(0xffffffffffffffff, 0x100bf64)
	/usr/local/go/src/runtime/os_darwin.go:54 +0x70
runtime.notesleep(0x1961200)
	/usr/local/go/src/runtime/lock_sema.go:167 +0xe3
runtime.stopm()
	/usr/local/go/src/runtime/proc.go:2016 +0xe3
runtime.exitsyscall0(0xc000094f00)
	/usr/local/go/src/runtime/proc.go:3193 +0x107
runtime.mcall(0x1056eeb)
	/usr/local/go/src/runtime/asm_amd64.s:299 +0x5b

goroutine 1 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0x9)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
cmd/go/internal/par.(*Work).Do(0xc00050c180, 0xa, 0xc00040cf60)
	/usr/local/go/src/cmd/go/internal/par/work.go:69 +0xbf
cmd/go/internal/modload.(*loader).load(0xc000280420, 0xc000151290)
	/usr/local/go/src/cmd/go/internal/modload/load.go:503 +0x73e
cmd/go/internal/modload.ImportPaths(0xc000232830, 0x1, 0x1, 0xc0002aac30, 0xc0002ac140, 0x38)
	/usr/local/go/src/cmd/go/internal/modload/load.go:164 +0x322
cmd/go/internal/load.ImportPaths(0xc000232830, 0x1, 0x1, 0xc000151500, 0x109affd, 0xc0002ac140)
	/usr/local/go/src/cmd/go/internal/load/pkg.go:1888 +0x62
cmd/go/internal/load.PackagesAndErrors(0xc000232830, 0x1, 0x1, 0x5, 0xc, 0x5)
	/usr/local/go/src/cmd/go/internal/load/pkg.go:1842 +0xa3
cmd/go/internal/load.PackagesForBuild(0xc000232830, 0x1, 0x1, 0xc000232830, 0x1, 0x1)
	/usr/local/go/src/cmd/go/internal/load/pkg.go:1897 +0x5d
cmd/go/internal/test.runTest(0x19563a0, 0xc0000d4020, 0x3, 0x3)
	/usr/local/go/src/cmd/go/internal/test/test.go:540 +0x179
main.main()
	/usr/local/go/src/cmd/go/main.go:219 +0x7d4

goroutine 35 [syscall, 19 minutes]:
os/signal.signal_recv(0x0)
	/usr/local/go/src/runtime/sigqueue.go:139 +0x9f
os/signal.loop()
	/usr/local/go/src/os/signal/signal_unix.go:23 +0x22
created by os/signal.init.0
	/usr/local/go/src/os/signal/signal_unix.go:29 +0x41

goroutine 37 [runnable]:
sync.(*Map).Load(0x195f720, 0x14cb620, 0xc0000fd010, 0x14b4400, 0xc000665728, 0x100b108)
	/usr/local/go/src/sync/map.go:104 +0xcb
cmd/go/internal/par.(*Cache).Do(0x195f720, 0x14cb620, 0xc0000fd010, 0xc000665778, 0x1511cc0, 0xc000665790)
	/usr/local/go/src/cmd/go/internal/par/work.go:120 +0x45
cmd/go/internal/modfetch.Lookup(0xc0000bea41, 0x1, 0x0, 0x0, 0x1626b80, 0xc00047c6a0)
	/usr/local/go/src/cmd/go/internal/modfetch/repo.go:193 +0xa4
cmd/go/internal/modload.Query(0xc0000bea41, 0x1, 0x1575012, 0x6, 0x15b2a28, 0x0, 0x1626b80, 0xc00047c6a0)
	/usr/local/go/src/cmd/go/internal/modload/query.go:135 +0x130
cmd/go/internal/modload.QueryPackage(0xc0000bea41, 0x4, 0x1575012, 0x6, 0x15b2a28, 0xc00012ec30, 0xc00054c058, 0xc000665d50, 0x100400d, 0xc000026949, ...)
	/usr/local/go/src/cmd/go/internal/modload/query.go:225 +0x202
cmd/go/internal/modload.Import(0xc0000bea41, 0x4, 0x3, 0x0, 0xc000665f00, 0x11c97bb, 0xc00012eb40, 0x179b59d8a9a5d809, 0xc000665f40, 0x11c999f)
	/usr/local/go/src/cmd/go/internal/modload/import.go:135 +0x6fe
cmd/go/internal/modload.(*loader).doPkg(0xc000280420, 0x14f5fc0, 0xc00043de00)
	/usr/local/go/src/cmd/go/internal/modload/load.go:614 +0x2f3
cmd/go/internal/modload.(*loader).doPkg-fm(0x14f5fc0, 0xc00043de00)
	/usr/local/go/src/cmd/go/internal/modload/load.go:503 +0x3e
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:101 +0x123
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

goroutine 40 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0xc)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

goroutine 43 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0xd)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

goroutine 42 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0xb)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

goroutine 39 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0xa)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

goroutine 38 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0xe)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

goroutine 41 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0x6)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

goroutine 44 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0x8)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

goroutine 45 [sync.Cond.Wait, 19 minutes]:
sync.runtime_notifyListWait(0xc00050c1c8, 0x7)
	/usr/local/go/src/runtime/sema.go:510 +0xeb
sync.(*Cond).Wait(0xc00050c1b8)
	/usr/local/go/src/sync/cond.go:56 +0x92
cmd/go/internal/par.(*Work).runner(0xc00050c180)
	/usr/local/go/src/cmd/go/internal/par/work.go:87 +0x33
created by cmd/go/internal/par.(*Work).Do
	/usr/local/go/src/cmd/go/internal/par/work.go:67 +0x9b

rax    0x104
rbx    0x13700
rcx    0x7ffeefbfe8f8
rdx    0x13700
rdi    0x1961440
rsi    0x1390100013a00
rbp    0x7ffeefbfe990
rsp    0x7ffeefbfe8f8
r8     0x0
r9     0x60
r10    0x0
r11    0x202
r12    0x1961440
r13    0x7ffeefbfe918
r14    0x1
r15    0x7fff8ef73340
rip    0x7fff5606ccee
rflags 0x203
cs     0x7
fs     0x0
gs     0x0

What did you expect to see?

Completion, error, or a timeout message.

It's probable this was a network issue of some sort, but go mod download completed successfully.

What did you see instead?

One CPU is pegged at 100% usage, and the go command doesn't complete.

The text was updated successfully, but these errors were encountered:

agnivade · 2018-09-18T04:07:53Z

SIGQUIT will dump the goroutine stack traces. Does the go command not exit after SIGQUIT ? Or it was already hung and you entered SIGQUIT to break out ?

alecthomas · 2018-09-18T04:46:29Z

The latter - I SIGQUIT after 20 minutes.

alecthomas · 2018-09-18T04:47:27Z

Interestingly this is no longer happening locally on my laptop, but IS still occurring reliably on our CI.

agnivade · 2018-09-18T05:57:07Z

Very interesting that -x does not show any output at all. Got a sample repo for us to test it out ?

agnivade · 2018-09-18T06:05:50Z

From the dump, it looks like all the runners are waiting on the mutex to be freed.

alecthomas · 2018-09-18T06:42:38Z

Got a sample repo for us to test it out ?

Unfortunately not, this is in a private corporate repository. Sorry I can't provide much more information than the above.

One other piece of data that may be useful: prior to this, go test was hanging, but also writing log messages about downloading a bunch of repos (eg. golang.org/x/arch/...). Each time I ran it it would attempt to download the same repos again but never succeed. Eventually I manually downloaded them each individually (via go get, if I recall correctly) at which point it no longer printed the message, but still hung.

agnivade · 2018-09-18T06:49:38Z

Just a shot in the dark. Have you tried go clean -modcache -r ?

alecthomas · 2018-09-18T07:10:29Z

I have yes, but also the CI doesn't keep state around, so it downloads from scratch each time.

odeke-em · 2018-09-18T08:37:49Z

@alecthomas thank you for reporting this issue and @agnivade too! I'll also tag @randall77 @aclements @ianlancetaylor since this involves the runtime scheduling and signals.

alecthomas · 2018-09-18T11:47:28Z

Okay, I think I've find out what the problem is. It's partially my fault, but the behaviour is still very surprising.

This is replicable by having the Go source extracted at the root of my package prior to running go test -x -v ./.... That said, it's pretty surprising that it doesn't complete doing whatever it's doing for >20 minutes.

bcmills · 2018-09-19T13:43:07Z

I'm not sure that there's anything more to be done here. Please let us know if you have ideas.

agnivade changed the title ~~go commands wedging trying to fetch modules~~ cmd/go: test gets hung Sep 18, 2018

agnivade added the NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one. label Sep 18, 2018

agnivade added this to the Go1.12 milestone Sep 18, 2018

bcmills closed this as completed Sep 19, 2018

golang locked and limited conversation to collaborators Sep 19, 2019

gopherbot added the FrozenDueToAge label Sep 19, 2019

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cmd/go: test gets hung #27720

cmd/go: test gets hung #27720

alecthomas commented Sep 18, 2018

agnivade commented Sep 18, 2018

alecthomas commented Sep 18, 2018

alecthomas commented Sep 18, 2018

agnivade commented Sep 18, 2018

agnivade commented Sep 18, 2018

alecthomas commented Sep 18, 2018 •

edited

agnivade commented Sep 18, 2018

alecthomas commented Sep 18, 2018

odeke-em commented Sep 18, 2018

alecthomas commented Sep 18, 2018

bcmills commented Sep 19, 2018

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cmd/go: test gets hung #27720

cmd/go: test gets hung #27720

Comments

alecthomas commented Sep 18, 2018

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

Does this issue reproduce with the latest release?

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

What did you do?

What did you expect to see?

What did you see instead?

agnivade commented Sep 18, 2018

alecthomas commented Sep 18, 2018

alecthomas commented Sep 18, 2018

agnivade commented Sep 18, 2018

agnivade commented Sep 18, 2018

alecthomas commented Sep 18, 2018 • edited

agnivade commented Sep 18, 2018

alecthomas commented Sep 18, 2018

odeke-em commented Sep 18, 2018

alecthomas commented Sep 18, 2018

bcmills commented Sep 19, 2018

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

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

alecthomas commented Sep 18, 2018 •

edited