cgo: hang on race condition between cmd.Run() and DNS lookup on macOS

[szabolcsgelencser]

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

$ go version
go version go1.18.4 darwin/amd64

Also present on older versions (tested on go1.16 and go1.17.11 as well).

Does this issue reproduce with the latest release?

Yes.

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

Easily reproducible (after a few tries) on macOS Monterey (both on ARM and Intel-based CPUs, tried on both macOS 12.2 and 12.4).

go env Output

$ go env
GO111MODULE="auto"
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/vagrant/Library/Caches/go-build"
GOENV="/Users/vagrant/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.18.4"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
GOWORK=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/11/nh0v1jld7zd7b9zqm1774gtm0000gn/T/go-build810501022=/tmp/go-build -gno-record-gcc-switches -fno-common"

We couldn't reproduce it on Linux (Ubuntu 20.04) and macOS Catalina (10.15.7) but we could very infrequently reproduce it on macOS Big Sur (11.6.8) as well.

What did you do?

Run https://go.dev/play/p/3gaoK8kU6Qb on macOS Monterey via for i in {1..100}; do go run main.go; echo $i; done, it usually hangs after ~10 runs.

What did you expect to see?

The command execution and HTTP request-related goroutines terminate, the main goroutine terminates, and the process exits.

What did you see instead?

• The process hangs forever, doesn't terminate.

• It (the main, parent process) is consuming 100% CPU.

• On cmd.Run() it succesfully fork-ed the parent process but the child never execve-ed (it still points to the parent process's binary).

• Stacktrace of hung process.

  
  

  SIGQUIT: quit
    PC=0x7ff8061223ea m=0 sigcode=0
  goroutine 0 [idle]:
  
  runtime.pthread_cond_wait(0x1450a00, 0x14509c0)
  
  /usr/local/go/src/runtime/sys_darwin.go:448 +0x34
  
  runtime.semasleep(0xffffffffffffffff)
  
  /usr/local/go/src/runtime/os_darwin.go:66 +0xad
  
  runtime.notesleep(0x14507c8)
  
  /usr/local/go/src/runtime/lock_sema.go:181 +0x85
  
  runtime.mPark(...)
  
  /usr/local/go/src/runtime/proc.go:1449
  
  runtime.stopm()
  
  /usr/local/go/src/runtime/proc.go:2228 +0x8d
  
  runtime.findrunnable()
  
  /usr/local/go/src/runtime/proc.go:2804 +0x865
  
  runtime.schedule()
  
  /usr/local/go/src/runtime/proc.go:3187 +0x239
  
  runtime.exitsyscall0(0xc000166820)
  
  /usr/local/go/src/runtime/proc.go:3938 +0x15b
  
  runtime.mcall()
  
  /usr/local/go/src/runtime/asm_amd64.s:425 +0x43
  goroutine 1 [semacquire]:
  
  sync.runtime_Semacquire(0xc000013490?)
  
  /usr/local/go/src/runtime/sema.go:56 +0x25
  
  sync.(*WaitGroup).Wait(0x1004631?)
  
  /usr/local/go/src/sync/waitgroup.go:136 +0x52
  
  main.main()
  
  /Users/vagrant/hanging-switch-workflow/main.go:46 +0x11d
  goroutine 250 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000398000)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 260 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000316120)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 251 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774568, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c6f00?, 0xc0003c2000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c6f00, {0xc0003c2000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c6f00, {0xc0003c2000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e388, {0xc0003c2000?, 0xc000010338?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000108fc0, {0xc0003c2000?, 0xc0003ad200?, 0xc00030bd30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039bc80)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039bc80, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000108fc0)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 213 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774ec8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0000ca200?, 0xc000436000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0000ca200, {0xc000436000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0000ca200, {0xc000436000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc0000103b0, {0xc000436000?, 0xc000010278?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc0001086c0, {0xc000436000?, 0xc00017a9c0?, 0xc0003a5d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc000179380)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc000179380, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc0001086c0)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 34 [syscall]:
  
  syscall.syscall(0xc00018cb18?, 0x106de0f?, 0xc00018cbe8?, 0xc0001a6400?)
  
  /usr/local/go/src/runtime/sys_darwin.go:22 +0x4e
  
  syscall.readlen(0x14802c0?, 0x144ff20?, 0x23?)
  
  /usr/local/go/src/syscall/syscall_darwin.go:234 +0x35
  
  syscall.forkExec({0x1278a7d?, 0xc00019df70?}, {0xc000182120?, 0x1?, 0x1?}, 0xc0001ad000?)
  
  /usr/local/go/src/syscall/exec_unix.go:221 +0x44c
  
  syscall.StartProcess(...)
  
  /usr/local/go/src/syscall/exec_unix.go:255
  
  os.startProcess({0x1278a7d, 0xe}, {0xc000182120, 0x1, 0x1}, 0xc00018cef8)
  
  /usr/local/go/src/os/exec_posix.go:54 +0x335
  
  os.StartProcess({0x1278a7d, 0xe}, {0xc000182120, 0x1, 0x1}, 0x100e045?)
  
  /usr/local/go/src/os/exec.go:109 +0x5a
  
  os/exec.(*Cmd).Start(0xc000190420)
  
  /usr/local/go/src/os/exec/exec.go:425 +0x5e5
  
  os/exec.(*Cmd).Run(0x1278a7d?)
  
  /usr/local/go/src/os/exec/exec.go:338 +0x1e
  
  main.main.func1()
  
  /Users/vagrant/hanging-switch-workflow/main.go:21 +0xd4
  
  created by main.main
  
  /Users/vagrant/hanging-switch-workflow/main.go:16 +0x33
  goroutine 208 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000398120)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 244 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000316240)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 254 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000109320)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 226 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000109440)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 255 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774748, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c6e80?, 0xc0003c6000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c6e80, {0xc0003c6000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c6e80, {0xc0003c6000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e398, {0xc0003c6000?, 0xc000010290?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc0001087e0, {0xc0003c6000?, 0xc0003ad2c0?, 0xc0003d8d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039be00)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039be00, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc0001087e0)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 215 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774a18, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c6d80?, 0xc000438000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c6d80, {0xc000438000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c6d80, {0xc000438000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc0000103c0, {0xc000438000?, 0xc000010308?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000108d80, {0xc000438000?, 0xc00017ac60?, 0xc00043fd30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc000179440)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc000179440, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000108d80)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 214 [select]:
  
  net/http.(*persistConn).writeLoop(0xc0001086c0)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 145 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774bf8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c6d00?, 0xc000432000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c6d00, {0xc000432000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c6d00, {0xc000432000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc0000103a0, {0xc000432000?, 0xc00018e330?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000398240, {0xc000432000?, 0xc00017a900?, 0xc0000bad30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc000179200)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc000179200, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000398240)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 257 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774838, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c6e00?, 0xc0003c8000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c6e00, {0xc0003c8000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c6e00, {0xc0003c8000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e3a0, {0xc0003c8000?, 0xc000010320?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000108ea0, {0xc0003c8000?, 0xc0003ad320?, 0xc0003dad30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039bec0)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039bec0, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000108ea0)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 247 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774478, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c6f80?, 0xc0003be000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c6f80, {0xc0003be000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c6f80, {0xc0003be000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e378, {0xc0003be000?, 0xc0000102a8?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000108900, {0xc0003be000?, 0xc0003ad140?, 0xc0003a2d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039bb00)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039bb00, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000108900)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 245 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774298, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c7000?, 0xc0003bc000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c7000, {0xc0003bc000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c7000, {0xc0003bc000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e370, {0xc0003bc000?, 0xc000010350?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc0001090e0, {0xc0003bc000?, 0xc0003ad0e0?, 0xc00031fd30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039ba40)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039ba40, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc0001090e0)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 203 [IO wait]:
  
  internal/poll.runtime_pollWait(0x17741a8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c7080?, 0xc0003b2000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c7080, {0xc0003b2000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c7080, {0xc0003b2000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e348, {0xc0003b2000?, 0xc0000102c0?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000108a20, {0xc0003b2000?, 0xc000344060?, 0xc0003a3d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039b680)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039b680, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000108a20)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 209 [IO wait]:
  
  internal/poll.runtime_pollWait(0x17740b8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c7100?, 0xc0003b8000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c7100, {0xc0003b8000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c7100, {0xc0003b8000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e360, {0xc0003b8000?, 0xc000010368?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000109200, {0xc0003b8000?, 0xc00017aba0?, 0xc0001b3d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039b8c0)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039b8c0, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000109200)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 211 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774dd8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0001c6c80?, 0xc000434000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0001c6c80, {0xc000434000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0001c6c80, {0xc000434000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc0000103a8, {0xc000434000?, 0xc0002862a0?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000316000, {0xc000434000?, 0xc00017a960?, 0xc00004bd30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc0001792c0)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc0001792c0, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000316000)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 259 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774b08, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0000ca300?, 0xc0003ca000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0000ca300, {0xc0003ca000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0000ca300, {0xc0003ca000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e3a8, {0xc0003ca000?, 0xc000286348?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000316120, {0xc0003ca000?, 0xc0003ad380?, 0xc0003d4d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039bf80)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039bf80, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000316120)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 249 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774388, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0000ca480?, 0xc0003c0000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0000ca480, {0xc0003c0000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0000ca480, {0xc0003c0000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e380, {0xc0003c0000?, 0xc00018e300?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000398000, {0xc0003c0000?, 0xc0003ad1a0?, 0xc0000b6d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039bbc0)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039bbc0, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000398000)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 253 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774928, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0000ca380?, 0xc0003c4000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0000ca380, {0xc0003c4000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0000ca380, {0xc0003c4000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e390, {0xc0003c4000?, 0xc000010380?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000109320, {0xc0003c4000?, 0xc0003ad260?, 0xc000321d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039bd40)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039bd40, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000109320)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 243 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774658, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0000ca400?, 0xc0003ba000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0000ca400, {0xc0003ba000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0000ca400, {0xc0003ba000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e368, {0xc0003ba000?, 0xc000286360?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000316240, {0xc0003ba000?, 0xc00017ac00?, 0xc00043ed30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039b980)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039b980, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000316240)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 161 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1774ce8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0000ca280?, 0xc000342000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0000ca280, {0xc000342000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0000ca280, {0xc000342000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc000286368, {0xc000342000?, 0xc000010398?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000109440, {0xc000342000?, 0xc00017aa20?, 0xc0000bbd30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00032b740)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00032b740, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000109440)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 207 [IO wait]:
  
  internal/poll.runtime_pollWait(0x1773fc8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0000ca500?, 0xc0003b6000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0000ca500, {0xc0003b6000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0000ca500, {0xc0003b6000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e358, {0xc0003b6000?, 0xc00018e318?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000398120, {0xc0003b6000?, 0xc0003ad3e0?, 0xc0003d6d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039b800)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039b800, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000398120)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 199 [IO wait]:
  
  internal/poll.runtime_pollWait(0x17c3fb8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc0002b5100?, 0xc0003ae000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc0002b5100, {0xc0003ae000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc0002b5100, {0xc0003ae000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e338, {0xc0003ae000?, 0xc0000102d8?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000108b40, {0xc0003ae000?, 0xc00017ab40?, 0xc0001b4d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039b500)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039b500, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000108b40)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 205 [IO wait]:
  
  internal/poll.runtime_pollWait(0x17c4198, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc00014e180?, 0xc0003b4000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc00014e180, {0xc0003b4000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc00014e180, {0xc0003b4000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e350, {0xc0003b4000?, 0xc0000102f0?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc000108c60, {0xc0003b4000?, 0xc0003440c0?, 0xc0003dcd30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039b740)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039b740, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc000108c60)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 201 [IO wait]:
  
  internal/poll.runtime_pollWait(0x17c40a8, 0x72)
  
  /usr/local/go/src/runtime/netpoll.go:302 +0x89
  
  internal/poll.(*pollDesc).wait(0xc00014e200?, 0xc0003b0000?, 0x0)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:83 +0x32
  
  internal/poll.(*pollDesc).waitRead(...)
  
  /usr/local/go/src/internal/poll/fd_poll_runtime.go:88
  
  internal/poll.(*FD).Read(0xc00014e200, {0xc0003b0000, 0x1000, 0x1000})
  
  /usr/local/go/src/internal/poll/fd_unix.go:167 +0x25a
  
  net.(*netFD).Read(0xc00014e200, {0xc0003b0000?, 0x1006b89?, 0x4?})
  
  /usr/local/go/src/net/fd_posix.go:55 +0x29
  
  net.(*conn).Read(0xc00018e340, {0xc0003b0000?, 0xc000010040?, 0x1?})
  
  /usr/local/go/src/net/net.go:183 +0x45
  
  net/http.(*persistConn).Read(0xc0001085a0, {0xc0003b0000?, 0xc0003ad440?, 0xc0003d7d30?})
  
  /usr/local/go/src/net/http/transport.go:1929 +0x4e
  
  bufio.(*Reader).fill(0xc00039b5c0)
  
  /usr/local/go/src/bufio/bufio.go:106 +0x103
  
  bufio.(*Reader).Peek(0xc00039b5c0, 0x1)
  
  /usr/local/go/src/bufio/bufio.go:144 +0x5d
  
  net/http.(*persistConn).readLoop(0xc0001085a0)
  
  /usr/local/go/src/net/http/transport.go:2093 +0x1ac
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1750 +0x173e
  goroutine 212 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000316000)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 210 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000398240)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 216 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000108d80)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 258 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000108ea0)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 256 [select]:
  
  net/http.(*persistConn).writeLoop(0xc0001087e0)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 252 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000108fc0)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 248 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000108900)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 246 [select]:
  
  net/http.(*persistConn).writeLoop(0xc0001090e0)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 204 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000108a20)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 242 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000109200)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 206 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000108c60)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 202 [select]:
  
  net/http.(*persistConn).writeLoop(0xc0001085a0)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  goroutine 200 [select]:
  
  net/http.(*persistConn).writeLoop(0xc000108b40)
  
  /usr/local/go/src/net/http/transport.go:2392 +0xf5
  
  created by net/http.(*Transport).dialConn
  
  /usr/local/go/src/net/http/transport.go:1751 +0x1791
  rax    0x104
  
  rbx    0x5044600
  
  rcx    0x7ff7bfefec58
  
  rdx    0xb00
  
  rdi    0x1450a00
  
  rsi    0x4f0100005000
  
  rbp    0x7ff7bfefed00
  
  rsp    0x7ff7bfefec58
  
  r8     0x0
  
  r9     0xa0
  
  r10    0x0
  
  r11    0x246
  
  r12    0x16
  
  r13    0x0
  
  r14    0x4f0100005000
  
  r15    0xb00
  
  rip    0x7ff8061223ea
  
  rflags 0x247
  
  cs     0x7
  
  fs     0x0
  
  gs     0x0
  
  exit status 2
  
  

• dtruss on the parent process doesn't report any syscalls. dtruss on the child process (created by cmd.Run()) reports __semwait_signal(0x903, 0x0, 0x1) = -1 Err#60 every few seconds.

• CGO_ENABLED=0 fixes the issue.

  • Following up on this, we've tried to reproduce the issue via pure C (to prove that this is a macOS issue and it has nothing to do with Go), trying to use the same syscalls as Go, but we failed to do so (https://gist.github.com/szabolcsgelencser/b5c0ff22765edc155c6e93cb1f46e338). Our latest assumption was that it has something to do with Go's CGO handling (acquiring OS threads to execute the C code on them aside from multiplexing goroutines on a set of OS threads, etc) but we reached the limit of our technical knowledge in this area.
  • Forcing usage of the Go-based DNS resolver (cgo is the default) via GODEBUG=netdns=go fixes the issue.

• unset-ig the __CF_USER_TEXT_ENCODING environment variable fixes the issue (similar to/same as os/exec: cmd.Output/StartProcess hangs on macOS 12.3 #52086 ?).

[ianferguson]

the __CF_USER_TEXT_ENCODING symptom matches #52086 and the trigger of a DNS lookup + a cmd.Run() call matches the reproduction case I have there as well: #52086 (comment)

[cherrymui]

@szabolcsgelencser @ianferguson thanks for the information. Sounds like this and #52086 are the same? (So we can close this and keep our discussion on #52086) Thanks.

[szabolcsgelencser]

Sure, I'm ok to go with #52086 :)