"Calling a function with a bad signature!"' failed.

[dpc]

I was able to crash compiler (rustc 1.0.0-nightly (522d09d 2015-02-19) (built 2015-02-21)
) :

rustc: /home/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/llvm/lib/IR/Instructions.cpp:281: void llvm::CallInst::init(llvm::Value*, llvm::ArrayRef<llvm::Value*>, const llvm::Twine&): Assertion `(i >= FTy->getNumParams() || FTy->getParamType(i) == Args[i]->getType()) && "Calling a function with a bad signature!"' failed.

with: https://github.com/dpc/rhex/tree/0dbf5b7f861638e59f367170b21b6b5ee9b286f7

and it turned out that this is a small change:

dpc/rhex@17487b8

that fixes the crash. I hope it's helpful.

[dotdash]

Thanks for the bug report!

Reduced testcase:

pub fn fail(x: Option<& (Iterator+Send)>) -> Option<&Iterator> {
    inner(x)
}

pub fn inner(x: Option<& (Iterator+Send)>) -> Option<&(Iterator+Send)> {
    x
}

fn main() {}

The problem is that LLVM gets distinct types for Option<&Trait> and Option<&(Trait+Bound)> and sees the call as invalid.

FWIW, you could also have changed your At::item() function to return Option<&'a (Item+Send+Sync)> to make the error go away