INTERNAL PANIC: runtime error: invalid memory address or nil pointer dereference
panic: (types.bailout) (0x54e860,0x23)
        panic: runtime error: invalid memory address or nil pointer dereference [recovered]
        panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x30 pc=0x446775]

goroutine 1 [running]:
code.google.com/p/go.tools/go/types.func·003()
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/check.go:120 +0x16a
code.google.com/p/go.tools/go/types.isUntyped(0x0, 0x0, 0x10039810)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/predicates.go:55 +0x25
code.google.com/p/go.tools/go/types.(*checker).callExpr(0xc21004c120, 0xc21004f8c0)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/expr.go:1012 +0x7e
code.google.com/p/go.tools/go/types.(*checker).err(0xc21004c120, 0x7f195dd00758, 0xc21000a6b0)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/errors.go:86 +0x89
code.google.com/p/go.tools/go/types.(*checker).errorf(0xc21004c120, 0x22, 0x5e6110, 0x13, 0xc2100544e0, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/errors.go:92 +0x1cd
code.google.com/p/go.tools/go/types.(*checker).rawExpr(0xc21004c120, 0xc21004f900, 0x7f195dd00d08, 0xc210042460, 0x0, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/expr.go:1057 +0x316
code.google.com/p/go.tools/go/types.(*checker).rawTyp(0xc21004c120, 0x7f195dd00d08, 0xc210042460, 0x0, 0x0, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/expr.go:1824 +0x88
code.google.com/p/go.tools/go/types.(*checker).typ(0xc21004c120, 0x7f195dd00d08, 0xc210042460, 0x0, 0x0, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/expr.go:1854 +0x48
code.google.com/p/go.tools/go/types.(*checker).collectFields(0xc21004c120, 0xc210039690, 0xc210042400, 0x0, 0x0, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/expr.go:193 +0x1f6
code.google.com/p/go.tools/go/types.(*checker).rawExpr(0xc21004c120, 0xc21004f8c0, 0x7f195dd00cd0, 0xc210042480, 0x0, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/expr.go:1760 +0x6e3a
code.google.com/p/go.tools/go/types.(*checker).rawTyp(0xc21004c120, 0x7f195dd00cd0, 0xc210042480, 0x0, 0x0, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/expr.go:1824 +0x88
code.google.com/p/go.tools/go/types.(*checker).typ(0xc21004c120, 0x7f195dd00cd0, 0xc210042480, 0x0, 0x0, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/expr.go:1854 +0x48
code.google.com/p/go.tools/go/types.(*checker).declareType(0xc21004c120, 0xc21004f880, 0x7f195dd00cd0, 0xc210042480, 
0xc210039700, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/resolver.go:479 +0xbb
code.google.com/p/go.tools/go/types.(*checker).declareObject(0xc21004c120, 0x7f195dd00a88, 0xc21004f880, 0xc210042400)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/resolver.go:351 +0x22a
code.google.com/p/go.tools/go/types.(*checker).resolveFiles(0xc21004c120, 0x7f195dc65e90, 0x1, 0x1, 0x6067a8, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/resolver.go:329 +0xda0
code.google.com/p/go.tools/go/types.check(0xc21004f700, 0x5c5320, 0x6, 0xc21004f580, 0x7f195dc65e90, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/check.go:157 +0x4ce
code.google.com/p/go.tools/go/types.(*Context).Check(0xc21004f700, 0x5c5320, 0x6, 0xc21004f580, 0x7f195dc65e90, ...)
        /home/dominikh/prj/go/src/code.google.com/p/go.tools/go/types/api.go:143 +0x6c
main.main()
        /tmp/demo.go:20 +0x1f8

goroutine 2 [runnable]:
exit status 2