Panic created by gopkg.in/mgo%2ev2.newCluster: invalid memory address

[Nicholas Skaggs]

As seen in:

http://reports.vapour.ws/releases/issue/580e7056749a561fa39305eb

gopkg.in/mgo%2ev2.newCluster in /gopkg.in/mgo.v2/cluster.go falls over, failing the juju package under test.

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x20 pc=0xb0e437]

goroutine 532 [running]:
panic(0x1b93000, 0xc08200c080)
 C:/Go/src/runtime/panic.go:481 +0x3f4
gopkg.in/mgo%2ev2.debugf(0x2143720, 0x2a, 0xc082623e98, 0x1, 0x1)
 c:/users/admini~1/appdata/local/temp/tmpusykc0/gogo/src/gopkg.in/mgo.v2/log.go:131 +0xa7
gopkg.in/mgo%2ev2.(*mongoCluster).syncServersLoop(0xc0825ca900)
 c:/users/admini~1/appdata/local/temp/tmpusykc0/gogo/src/gopkg.in/mgo.v2/cluster.go:399 +0x1c4
created by gopkg.in/mgo%2ev2.newCluster
 c:/users/admini~1/appdata/local/temp/tmpusykc0/gogo/src/gopkg.in/mgo.v2/cluster.go:78 +0x1dc
FAIL github.com/juju/juju/worker/apiaddressupdater 6.427s

[Anastasia (anastasia-macmood)]

I could not reproduce this locally under stress. It must have been fixed as part of another work item.