import strformat and fmt"foo" doesn't work: Error: undeclared identifier
```
>>> import strformat
>>> fmt"asdf"
inim_1530775518.nim(2, 6) Error: undeclared identifier: 'fmtRes194003'
>>> let a=fmt"asdf"
Error: undeclared identifier: 'fmtRes194003'
```

nim c -r test1.nim
works
with:
```
cat test1.nim
import strformat

let a=fmt"asdf"
echo a
```