What steps will reproduce the problem?
1. go get launchpad.net/juju-core/...
2. go test launchpad.net/juju-core/worker/upgrader

What is the expected output? What do you see instead?

Expected: tests pass

Got:

runtime: invalid GC instruction 0xc92ce0 at 0xc2085770c8
fatal error: scanblock: invalid GC instruction

runtime stack:
runtime.throw(0x1253b49)
        /home/dfc/go/src/pkg/runtime/panic.c:464 +0x69
scanblock(0x7fbcb85a3000, 0x7fbcb27fbc00)
        /home/dfc/go/src/pkg/runtime/mgc0.c:1149 +0x375
markroot(0xc20800c480, 0x45)
        /home/dfc/go/src/pkg/runtime/mgc0.c:1342 +0xd9
runtime.parfordo(0xc20800c480)
        /home/dfc/go/src/pkg/runtime/parfor.c:88 +0xa3
gc(0xc208588c30)
        /home/dfc/go/src/pkg/runtime/mgc0.c:2318 +0x1ba
mgc(0xc208606a20)
        /home/dfc/go/src/pkg/runtime/mgc0.c:2264 +0x2e
runtime.mcall(0x955c7c)
        /home/dfc/go/src/pkg/runtime/asm_amd64.s:181 +0x4b

Please use labels and text to provide additional information.

go version devel +dfc6bcfa4626 Fri Feb 28 21:45:12 2014 +1100 linux/amd64

I am sorry I cannot produce a smaller reproduction, hopefully you do not need to install
mongodb to make the tests pass.

Full panic, which points to reflect, is attached

Attachments:

1. t (47754 bytes)