Data race

[AlekSi]

Commit 82f1514.

$ go env
GOARCH="amd64"
GOBIN="/Users/aleksi/Code/Restream/pipe/bin"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/aleksi/Code/Restream/pipe"
GORACE="halt_on_error=1"
GOROOT="/usr/local/Cellar/go/1.7.5/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.7.5/libexec/pkg/tool/darwin_amd64"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/fl/c3xvc0tj1js__3jnrnbkjll40000gn/T/go-build078993110=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"

Installed dep with go get -u -race github.com/golang/dep/....

$ dep ensure -v -update
==================
WARNING: DATA RACE
Read at 0x00c420264c08 by main goroutine:
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*gitSource).doListVersions()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/vcs_source.go:187 +0x780
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*gitSource).listVersions()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/vcs_source.go:119 +0x408
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*SourceMgr).ListVersions()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/source_manager.go:395 +0x20d
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*bridge).ListVersions()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/bridge.go:94 +0x23f
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*solver).unselectedComparator()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/solver.go:991 +0x4d5
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*solver).(github.com/golang/dep/vendor/github.com/sdboyer/gps.unselectedComparator)-fm()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/solver.go:276 +0x55
  github.com/golang/dep/vendor/github.com/sdboyer/gps.unselected.Less()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/selection.go:160 +0x47
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*unselected).Less()
      <autogenerated>:84 +0xa5
  container/heap.up()
      /usr/local/Cellar/go/1.7.5/libexec/src/container/heap/heap.go:93 +0x71
  container/heap.Push()
      /usr/local/Cellar/go/1.7.5/libexec/src/container/heap/heap.go:54 +0x8f
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*solver).selectRoot()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/solver.go:479 +0x93b
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*solver).Solve()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/solver.go:312 +0xa6
  main.(*ensureCommand).Run()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/cmd/dep/ensure.go:144 +0x611
  main.main()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/cmd/dep/main.go:96 +0x84f

Previous write at 0x00c420264c08 by goroutine 25:
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*baseVCSSource).checkExistence()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/source.go:303 +0x273
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*baseVCSSource).ensureCacheExistence()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/source.go:257 +0x55
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*baseVCSSource).syncLocal.func1()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/source.go:328 +0x52
  sync.(*Once).Do()
      /usr/local/Cellar/go/1.7.5/libexec/src/sync/once.go:44 +0xf2
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*baseVCSSource).syncLocal()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/source.go:352 +0x8b
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*gitSource).syncLocal()
      <autogenerated>:237 +0x50
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*SourceMgr).SyncSourceFor()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/source_manager.go:461 +0x1a1
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*bridge).SyncSourceFor()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/bridge.go:353 +0x7d

Goroutine 25 (running) created at:
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*solver).selectRoot()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/solver.go:474 +0xb2e
  github.com/golang/dep/vendor/github.com/sdboyer/gps.(*solver).Solve()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/vendor/github.com/sdboyer/gps/solver.go:312 +0xa6
  main.(*ensureCommand).Run()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/cmd/dep/ensure.go:144 +0x611
  main.main()
      /Users/aleksi/Soft/GOPATH/src/github.com/golang/dep/cmd/dep/main.go:96 +0x84f
==================

[AlekSi]

Probably due to sdboyer/gps#170.

[sdboyer]

Yeah, that's likely the cause. Unfortunately, there are a few issues in the way of making progress there 😞 Trying to get to it as fast as I can!

Did the issue reliably re-occur, or just the once?

[sdboyer]

This oughtta be fixed once we merge in the latest gps, now that sdboyer/gps#196 is done