No compile-time error when referencing non-public module

[joshuawarner32]

The following produces a difficult to understand link error, rather than a compile error. Rust 0.7, ubuntu 12.04 x86_64.

hello.rs:

extern mod world;

fn main() {
  println("hello " + world::columbus::explore());
}

world.rs:

#[ link(name = "world",
        vers = "0.1")];

#[ crate_type = "lib" ];

mod columbus {
  pub fn explore() -> &str { "world" }
}

Compiling hello.rs gives this error:
error: linking with cc failed with code 1
note: cc arguments: -L/usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib -m64 -o hello hello.o -L/usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib -lstd-6c65cf4b443341b1-0.7 -L. -lworld-15fb3a718ea23983-0.1 -lrustrt -lrt -lpthread -L. -lrt -ldl -lm -lmorestack -lrustrt -Wl,-rpath,$ORIGIN/../../../../../usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib -Wl,-rpath,$ORIGIN/. -Wl,-rpath,/usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib -Wl,-rpath,/tmp/test/.
note: hello.o: In function main::_f3d4197390d6bb2a::_0$x2e0': hello.rc:(.text+0x54): undefined reference tocolumbus::explore::_3de4895354bdc485::_0$x2e1'
collect2: ld returned 1 exit status

[chris-morgan]

The problem here which should have been reported by the compiler is that columbus is private.

[alexcrichton]

I believe that this would be solved by #8365

[alexcrichton]

This has since been fixed to be a proper privacy error. There are plenty of tests in the testsuite for this, so I'm just going to close this.

The fixing pull request was #9735 for reference.