```
>>> Lint for src/future/FutureProxy.php:
Error (PHL1) Unknown Symbol
Use of unknown function 'qqqqqq'. Common causes are:
- Your libphutil/ is out of date.
This is the most common cause.
Update this copy of libphutil: /INSECURE/devtools/libphutil
- Some other library is out of date.
Update the library this symbol appears in.
- This symbol is misspelled.
Spell the symbol name correctly.
Symbol name spelling is case-sensitive.
- This symbol was added recently.
Run `arc liberate` on the library it was added to.
- This symbol is external. Use `@phutil-external-symbol`.
Use `grep` to find usage examples of this directive.
*** ALTHOUGH USUALLY EASY TO FIX, THIS IS A SERIOUS ERROR.
*** THIS ERROR IS YOUR FAULT. YOU MUST RESOLVE IT.
15 $this->setProxiedFuture($proxied);
16 }
17
>>> 18 qqqqqq();
19 }
20
21 public function setProxiedFuture(Future $proxied) {
```