cmd/link: TestMachoWrite fails

[gpaul]

If I run the cmd/link short tests with -cpu 1 they pass.
If I run the cmd/link short tests with -cpu 2 they pass.
If I run the cmd/link short tests with -cpu 1,2 TestMachoWrite fails with index out of
range.

I'm guessing that they stomp on each other.

Steps to reproduce:
  hg clone https://code.google.com/p/go/ 
  export GOROOT=`pwd`/go
  cd go/src
  ./make.bash 
  go test -short -cpu 1 cmd/link # pass
  go test -short -cpu 2 cmd/link # pass
  go test -short -cpu 1,2 cmd/link # fail

$ go test -v -short -cpu 1 cmd/link 
=== RUN TestLinkHello
--- PASS: TestLinkHello (0.00 seconds)
=== RUN TestMachoWrite
--- PASS: TestMachoWrite (0.00 seconds)
PASS
ok      cmd/link    0.004s

$ go test -v -short -cpu 2 cmd/link 
=== RUN TestLinkHello-2
--- PASS: TestLinkHello-2 (0.00 seconds)
=== RUN TestMachoWrite-2
--- PASS: TestMachoWrite-2 (0.00 seconds)
PASS
ok      cmd/link    0.004s

$ go test -v -short -cpu 1,2 cmd/link 
=== RUN TestLinkHello
--- PASS: TestLinkHello (0.00 seconds)
=== RUN TestMachoWrite
--- PASS: TestMachoWrite (0.00 seconds)
=== RUN TestLinkHello-2
--- PASS: TestLinkHello-2 (0.00 seconds)
=== RUN TestMachoWrite-2
--- FAIL: TestMachoWrite-2 (0.00 seconds)
panic: runtime error: slice bounds out of range [recovered]
    panic: runtime error: slice bounds out of range

goroutine 6 [running]:
runtime.panic(0x5b9ba0, 0x80fdea)
    /home/gustav/tmpgo4/go/src/pkg/runtime/panic.c:264 +0xb6
testing.func·005()
    /home/gustav/tmpgo4/go/src/pkg/testing/testing.go:385 +0xe8
runtime.panic(0x5b9ba0, 0x80fdea)
    /home/gustav/tmpgo4/go/src/pkg/runtime/panic.c:246 +0x106
cmd/link.machoRead(0x301000007, 0xc2100ad200, 0x200d, 0x21b8, 0xc21004e640, ...)
    /home/gustav/tmpgo4/go/src/cmd/link/macho_test.go:339 +0x2fbf
cmd/link.TestMachoWrite(0xc210070510)
    /home/gustav/tmpgo4/go/src/cmd/link/macho_test.go:184 +0x2d2
testing.tRunner(0xc210070510, 0x80aab8)
    /home/gustav/tmpgo4/go/src/pkg/testing/testing.go:391 +0x8b
created by testing.RunTests
    /home/gustav/tmpgo4/go/src/pkg/testing/testing.go:471 +0x958

goroutine 1 [chan receive]:
testing.RunTests(0x643dd8, 0x80aaa0, 0x2, 0x2, 0x1)
    /home/gustav/tmpgo4/go/src/pkg/testing/testing.go:472 +0x97b
testing.Main(0x643dd8, 0x80aaa0, 0x2, 0x2, 0x814120, ...)
    /home/gustav/tmpgo4/go/src/pkg/testing/testing.go:403 +0x8c
main.main()
    /dev/shm/go-build803010548/cmd/link/_test/_testmain.go:49 +0x9c
exit status 2
FAIL    cmd/link    0.006s

Which compiler are you using (5g, 6g, 8g, gccgo)?
6g


Which operating system are you using?
Linux 3.12.5-200.fc19.x86_64 #1 SMP Tue Dec 17 22:21:14 UTC 2013 x86_64 x86_64 x86_64
GNU/Linux

Which version are you using?  (run 'go version')
running tip.
go version devel +270e6a19b4ec Mon Jan 13 11:25:48 2014 +1100 linux/amd64

[davecheney]

Comment 1:

This is a test bug. The test probably doesn't leave the test fixture untouched after the
first run so fails to process the changed fixture on the second run.
go test -v -short -cpu 1,1 cmd/link
Also fails, showing this is not related to concurrency.

Labels changed: added release-none, repo-main, suggested.

Status changed to Accepted.

[bradfitz]

Comment 2:

This issue was closed by revision 86ac618.

Status changed to Fixed.