Comment 5 for bug 1356500

OK, this is becoming interesting, since i found an already unnoticed panic that is raised after a relation_set command
is performed, since the relation_set command doesn't returns any non-zero exit code, the charm installation succeed,
which explains why the relation data is missed.

Panic traceback

2014-08-12 11:06:09 DEBUG worker.uniter.jujuc server.go:104 hook context id "keystone/0:config-changed:6969413113383759108"; dir "/var/lib/juju/agents/unit-keystone-0/charm"
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x20 pc=0x5bd970]

goroutine 15439 [running]:
runtime.panic(0xcdad60, 0x1a86648)
 /usr/lib/go/src/pkg/runtime/panic.c:266 +0xb6
launchpad.net/juju-core/worker/uniter/jujuc.(*RelationSetCommand).Run(0xc210253750, 0xc210203050, 0x7fc83a9dbe80, 0xc21008d4d0)
 /build/buildd/juju-core-1.18.1/src/launchpad.net/juju-core/worker/uniter/jujuc/relation-set.go:68 +0x340
launchpad.net/juju-core/cmd.Main(0x7fc83a9efe58, 0xc210253750, 0xc210203050, 0xc2102255a0, 0x11, ...)
 /build/buildd/juju-core-1.18.1/src/launchpad.net/juju-core/cmd/cmd.go:244 +0x283
launchpad.net/juju-core/worker/uniter/jujuc.(*Jujuc).Main(0xc21029ab50, 0xc2102536c0, 0x2d, 0xc2102536f0, 0x2a, ...)
 /build/buildd/juju-core-1.18.1/src/launchpad.net/juju-core/worker/uniter/jujuc/server.go:105 +0x5fd
reflect.Value.call(0xc59b80, 0xc87a70, 0x130, 0xe019d0, 0x4, ...)
 /usr/lib/go/src/pkg/reflect/value.go:474 +0xe0b
reflect.Value.Call(0xc59b80, 0xc87a70, 0x130, 0x7fc83a848ee8, 0x3, ...)
 /usr/lib/go/src/pkg/reflect/value.go:345 +0x9d
net/rpc.(*service).call(0xc210090bc0, 0xc210090b80, 0xc210174b00, 0xc2101e7800, 0xc210247920, ...)
 /usr/lib/go/src/pkg/net/rpc/server.go:381 +0x159
created by net/rpc.(*Server).ServeCodec
 /usr/lib/go/src/pkg/net/rpc/server.go:452 +0x3bb