RefC build error returns 0 code

[joelberkeley]

The following file

module Main

import System.FFI

%foreign "C:foo,libfoo,foo.h"
foo : Int -> Int

main : IO ()
main = printLn $ foo 1

with no headers present, logs an error as expected:

$ idris2 --cg refc --build tinker.ipkg 
Now compiling the executable: tinker
build/exec/tinker.c:4:10: fatal error: foo.h: No such file or directory
    4 | #include <foo.h>
      |          ^~~~~~~
compilation terminated.

but mistakenly returns code 0.