Issue 1:
trait FTErrorMethods {
fn succeeded(self) -> bool;
}

impl FTErrorMethods for int {
fn succeeded(self) -> bool { self == 0 }
}

fn main() {
5.succeeded();
}

rustc: /run/media/jdm/ssd/rust/src/llvm/lib/VMCore/Instructions.cpp:2383: static llvm::CastInst* llvm::CastInst::CreatePointerCast(llvm::Value*, llvm::Type*, const llvm::Twine&, llvm::Instruction*): Assertion `S->getType()->isPointerTy() && "Invalid cast"' failed.

#4 0x00007ffff62dc216 in llvm::CastInst::CreatePointerCast(llvm::Value*, llvm::Type*, llvm::Twine const&, llvm::Instruction*) () from /usr/local/bin/../lib/librustllvm.so
#5 0x00007ffff6268fe0 in llvm::IRBuilder<true, llvm::ConstantFolder, llvm::IRBuilderDefaultInserter<true> >::CreatePointerCast(llvm::Value*, llvm::Type*, llvm::Twine const&) ()
from /usr/local/bin/../lib/librustllvm.so
#6 0x00007ffff6265f35 in LLVMBuildPointerCast () from /usr/local/bin/../lib/librustllvm.so
#7 0x00007ffff74191c2 in LLVMBuildPointerCast__c_stack_shim () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#8 0x00007ffff54e7649 in __morestack () from /usr/local/bin/../lib/librustrt.so
#9 0x00007ffff54d8104 in call_on_c_stack (fn_ptr=0x7ffff7419180, args=0x7fffe849a998, this=0x7ffff0108830) at /run/media/jdm/ssd/rust/src/rt/rust_task.h:478
#10 upcall_call_shim_on_c_stack (args=0x7fffe849a998, fn_ptr=0x7ffff7419180) at /run/media/jdm/ssd/rust/src/rt/rust_upcall.cpp:64
#11 0x00007ffff6d9c09a in middle::trans::build::PointerCast::_aee05de3d6b51f11::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#12 0x00007ffff6ddd6ce in middle::trans::callee::trans_call_inner::anon::expr_fn_27457 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#13 0x00007ffff6d991cc in middle::trans::base::with_scope::_518696e6502795b0::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#14 0x00007ffff6dcf435 in middle::trans::callee::trans_method_call::_12bb7b81ca47a09::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#15 0x00007ffff6de983c in middle::trans::expr::trans_rvalue_dps_unadjusted::_cbdc4c02519225::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#16 0x00007ffff6de4b64 in middle::trans::expr::trans_to_datum_unadjusted::_a2a3224b30364953::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#17 0x00007ffff6d50cc0 in middle::trans::expr::trans_to_datum::_a2a3224b30364953::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#18 0x00007ffff6de7d4e in middle::trans::expr::trans_rvalue_datum_unadjusted::_a2a3224b30364953::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#19 0x00007ffff6de47fa in middle::trans::expr::trans_to_datum_unadjusted::_a2a3224b30364953::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#20 0x00007ffff6d50cc0 in middle::trans::expr::trans_to_datum::_a2a3224b30364953::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#21 0x00007ffff6d4e7ca in middle::trans::controlflow::trans_if::_fcc7ad9922f2f49::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#22 0x00007ffff6de9c99 in middle::trans::expr::trans_rvalue_dps_unadjusted::_cbdc4c02519225::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#23 0x00007ffff6d4de34 in middle::trans::expr::trans_into::_cbdc4c02519225::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#24 0x00007ffff7434814 in __morestack () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#25 0x00007ffff6d4cf3d in middle::trans::base::trans_stmt::_d936d389a86c7a66::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#26 0x00007ffff6d4c426 in middle::trans::controlflow::trans_block::anon::expr_fn_21837 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#27 0x00007ffff6d4a66e in middle::trans::controlflow::trans_block::_84b7ff1756c49e1::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#28 0x00007ffff6e513b7 in middle::trans::base::trans_closure::_33dc6c6bc3c467::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#29 0x00007ffff6d03624 in middle::trans::base::trans_fn::_bbb928f648ebbdfa::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#30 0x00007ffff6cfb180 in middle::trans::base::trans_item::_e5c80d83455a852::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#31 0x00007ffff6e57e30 in middle::trans::base::trans_mod::_f6b5437a924015ec::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#32 0x00007ffff6e75e5b in middle::trans::base::trans_crate::_685731d1dcd33aec::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#33 0x00007ffff73f4993 in driver::driver::compile_rest::_3dc0cd32a85c34a0::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#34 0x00007ffff7434814 in __morestack () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#35 0x00007ffff73f6ef7 in driver::driver::compile_upto::_23bd5d90dda9e867::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#36 0x00007ffff7434814 in __morestack () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#37 0x00007ffff73f72f9 in driver::driver::compile_input::_594ffb6142f762a7::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#38 0x00007ffff742542f in run_compiler::_c936523e1243e7f::_06 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#39 0x00007ffff7432151 in monitor::anon::expr_fn_82369 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#40 0x00007ffff742e57b in task::__extensions__::try_81880::anon::expr_fn_82143 () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#41 0x00007ffff7434814 in __morestack () from /usr/local/bin/../lib/librustc-c84825241471686d-0.6.so
#42 0x00007ffff7df363a in task::spawn::spawn_raw::make_child_wrapper::anon::expr_fn_11480 () from /usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.6.so
#43 0x00007ffff7e5aa20 in __morestack () from /usr/local/bin/../lib/libcore-c3ca5d77d81b46c1-0.6.so
#44 0x00007ffff54d70a4 in task_start_wrapper (a=0x7ffff0109660) at /run/media/jdm/ssd/rust/src/rt/rust_task.cpp:162
#45 0x0000000000000000 in ?? ()

Issue 2:
trait Foo {} impl Foo {} fn main() {}

Gives

<anon>:1:14: 1:25 error: duplicate definition of module `Foo`
<anon>:1 trait Foo {} impl Foo {} fn main() {}
^~~~~~~~~~~
<anon>:1:1: 1:13 note: first definition of module `Foo` here
<anon>:1 trait Foo {} impl Foo {} fn main() {}
^~~~~~~~~~~~
error: aborting due to previous error

There's no mention of mods in the code, so it would be nice if the error message didn't mention modules at all; and preferably if it just complained that the Foo in impl Foo {} wasn't a type. (Of course, the latter point may change with DST.)