testing.go invalid memory address or nil pointer dereference

[Werner Hattingh]

Ok so i have found that my one unit test fails intermittently. Every
now and then I get "panic: runtime error: invalid memory address or
nil pointer dereference
" that did not make sense. Traced it to testing.go and add 3 prints:

--- a/src/pkg/testing/testing.go Fri Feb 24 22:42:16 2012 +1100
+++ b/src/pkg/testing/testing.go Thu Mar 01 13:14:21 2012 +0000
@@ -292,6 +292,10 @@
}

func (t *T) report() {
+ fmt.Printf("t %v\n", t )
+ fmt.Printf("t.duration %v\n", t.duration )
+ fmt.Printf("t.duration.Seconds() %v\n", t.duration.Seconds() )
+
tstr := fmt.Sprintf("(%.2f seconds)", t.duration.Seconds())
format := "--- %s: %s %s\n%s"
if t.failed {


OUTPUT at end:

t <nil>
panic: runtime error: invalid memory address or nil pointer
dereference
[signal 0xb code=0x1 addr=0x30 pc=0x422be5]

goroutine 2 [running]:
testing.(*T).report(0x0, 0x63d1c8)
/home/whattingh/go/src/pkg/testing/testing.go:296 +0xf1
testing.RunTests(0x400c00, 0x7d3028, 0x1200000012, 0xf8400d2b01,
0xf8400d7430, ...)
/home/whattingh/go/src/pkg/testing/testing.go:359 +0x80c
testing.Main(0x400c00, 0x7d3028, 0x1200000012, 0x7d5ea0, 0x0, ...)
/home/whattingh/go/src/pkg/testing/testing.go:282 +0x62
main.main()
/tmp/go-build452141823/next/registry/server/_test/_testmain.go:77
+0x91
created by _rt0_amd64
/home/whattingh/go/src/pkg/runtime/asm_amd64.s:69 +0xd1

goroutine 1 [syscall]:

goroutine 3 [syscall]:
created by addtimer
/home/whattingh/go/src/pkg/runtime/ztime_amd64.c:69

goroutine 6 [syscall]:
syscall.Syscall6()
/home/whattingh/go/src/pkg/syscall/asm_linux_amd64.s:40 +0x5
syscall.EpollWait(0xf800000009, 0xf8400ca220, 0xa0000000a, 0xffffffff,
0xc, ...)
/home/whattingh/go/src/pkg/syscall/zerrors_linux_amd64.go:1781 +0xa1
net.(*pollster).WaitFD(0xf8400ca210, 0xf8400db7c0, 0x0, 0x0, 0x0, ...)
/home/whattingh/go/src/pkg/net/fd_linux.go:145 +0x110
net.(*pollServer).Run(0xf8400db7c0, 0x0)
/home/whattingh/go/src/pkg/net/fd.go:236 +0xe4
created by net.newPollServer
/home/whattingh/go/src/pkg/net/newpollserver.go:35 +0x382
exit status 2
FAIL next/registry/server 2.098s

My test func:
func TestRegisterMax(t *testing.T)

I do not use the testing variable in my test function. I do not have
a gobal var "t".

I have know i idea at this moment anymore what to do.

Please help

[chris dollin]

On 1 March 2012 13:21, Werner Hattingh <werner....@gmail.com> wrote:

> My test func:
> func TestRegisterMax(t *testing.T)

The function has a body, yes? What's in it?

Chris

--
Chris "allusive" Dollin

[Russ Cox]

On Thu, Mar 1, 2012 at 08:21, Werner Hattingh <werner....@gmail.com> wrote:
> t <nil>
> panic: runtime error: invalid memory address or nil pointer
> dereference
> [signal 0xb code=0x1 addr=0x30 pc=0x422be5]
>
> goroutine 2 [running]:
> testing.(*T).report(0x0, 0x63d1c8)
>        /home/whattingh/go/src/pkg/testing/testing.go:296 +0xf1
> testing.RunTests(0x400c00, 0x7d3028, 0x1200000012, 0xf8400d2b01,
> 0xf8400d7430, ...)
> /home/whattingh/go/src/pkg/testing/testing.go:359 +0x80c

There's memory corruption somewhere. t is a local variable
in RunTests's call t.report() and yet it has been zeroed somehow.
Can you reduce this to a program you are willing to share?
If so, please file an issue at http://code.google.com/p/go/issues/list
and attach the program.

Thanks.
Russ