go1.8 can't iterate over map while writing to it

[geomantic_omen]

I upgrade golang to 1.8 and encounter this panic while using cache2go:

goroutine 363453 [running]:
runtime.throw(0x94121a, 0x26)
/usr/local/go/src/runtime/panic.go:596 +0x95 fp=0xc420513de0 sp=0xc420513dc0
runtime.mapiternext(0xc420513f68)
/usr/local/go/src/runtime/hashmap.go:737 +0x7ee fp=0xc420513e90 sp=0xc420513de0
github.com/muesli/cache2go.(*CacheTable).expirationCheck(0xc4201d2540)
/Users/geomantic/Documents/develop/gopath/src/github.com/muesli/cache2go/cachetable.go:111 +0x336 fp=0xc4205 13fd8 sp=0xc420513e90
runtime.goexit()
/usr/local/go/src/runtime/asm_amd64.s:2197 +0x1 fp=0xc420513fe0 sp=0xc420513fd8
created by github.com/muesli/cache2go.(*CacheTable).expirationCheck.func1
/Users/geomantic/Documents/develop/gopath/src/github.com/muesli/cache2go/cachetable.go:137 +0x3e

[Steven086]

solved?

[Zhaohu Xing]

solved?

[Christian Muehlhaeuser]

Working on it.