```
dub upgrade
Upgrading project in L:\Users\laszl\Documents\GitHub\iota\Warning Sub package nulib:os_posix, referenced by nulib dub.package_.Package must be referenced using the path to its base package Warning Sub package nulib:os_win32, referenced by nulib dub.package_.Package must be referenced using the path to its base package
```
These in turn likely cause files contained within the subpackages to not be found by the compiler.
