Issue 1:
Test case:

fn main() {
let x = 2i;
let _y = move || x;
}

Output:

rustc: /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/llvm/include/llvm/Support/Casting.h:237: typename llvm::cast_retty<X, Y*>::ret_type llvm::cast(Y*) [with X = llvm::PointerType; Y = llvm::Type; typename llvm::cast_retty<X, Y*>::ret_type = llvm::PointerType*]: Assertion `isa<X>(Val) && "cast<Ty>() argument of incompatible type!"' failed.
Aborted

Issue 2:
STR

fn main() {
let n = 0u;

let f = move || n += 1;
}

Output

rustc: /var/tmp/paludis/build/dev-lang-rust-scm/work/rust-scm/src/llvm/include/llvm/Support/Casting.h:237: typename llvm::cast_retty<X, Y*>::ret_type llvm::cast(Y*) [with X = llvm::PointerType; Y = llvm::Type; typename llvm::cast_retty<X, Y*>::ret_type = llvm::PointerType*]: Assertion `isa<X>(Val) && "cast<Ty>() argument of incompatible type!"' failed.

Program received signal SIGABRT, Aborted.
[Switching to Thread 0x7fffeffff480 (LWP 12192)]
0x00007ffff6f638a7 in raise () from /lib64/libc.so.6
(gdb) backtrace
#0 0x00007ffff6f638a7 in raise () from /lib64/libc.so.6
#1 0x00007ffff6f64c3a in abort () from /lib64/libc.so.6
#2 0x00007ffff6f5c7fd in __assert_fail_base () from /lib64/libc.so.6
#3 0x00007ffff6f5c8b2 in __assert_fail () from /lib64/libc.so.6
#4 0x00007ffff261305c in ?? () from /usr/lib64/librustc_llvm-4e7c5e5c.so
#5 0x00007ffff33413ac in llvm::LoadInst::LoadInst(llvm::Value*, char const*, bool, llvm::Instruction*) () from /usr/lib64/librustc_llvm-4e7c5e5c.so
#6 0x00007ffff32a29bf in LLVMBuildLoad () from /usr/lib64/librustc_llvm-4e7c5e5c.so
#7 0x00007ffff7773334 in trans::builder::Builder$LT$$x27a$C$$x20$x27tcx$GT$::load::h3c2c0a39157367b2Gsr () from /usr/lib64/librustc_trans-4e7c5e5c.so
#8 0x00007ffff76f6f32 in trans::build::Load::hb999a33dee821b74Jnq () from /usr/lib64/librustc_trans-4e7c5e5c.so
#9 0x00007ffff772cc52 in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#10 0x00007ffff7720e0a in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#11 0x00007ffff76dd854 in trans::expr::trans_into::h7dc261a5d77d2dbciQh () from /usr/lib64/librustc_trans-4e7c5e5c.so
#12 0x00007ffff76ddadd in trans::controlflow::trans_block::h40e78d4cabd8c783p2d () from /usr/lib64/librustc_trans-4e7c5e5c.so
#13 0x00007ffff7790e50 in trans::base::trans_closure::h9baffc02e3bf0daf6Au () from /usr/lib64/librustc_trans-4e7c5e5c.so
#14 0x00007ffff7732f6e in trans::closure::trans_expr_fn::h04ecc83b7400adfaVWy () from /usr/lib64/librustc_trans-4e7c5e5c.so
#15 0x00007ffff771efca in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#16 0x00007ffff76dd746 in trans::expr::trans_into::h7dc261a5d77d2dbciQh () from /usr/lib64/librustc_trans-4e7c5e5c.so
#17 0x00007ffff77d64cd in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#18 0x00007ffff77d58b4 in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#19 0x00007ffff77881f4 in trans::_match::store_local::hdd8a0d2165cb659fx9x () from /usr/lib64/librustc_trans-4e7c5e5c.so
#20 0x00007ffff76dcd0e in trans::base::init_local::h0bd956a2c65b5d51NIt () from /usr/lib64/librustc_trans-4e7c5e5c.so
#21 0x00007ffff76dc332 in trans::controlflow::trans_stmt::h3a5fa88dc3d60c9fhXd () from /usr/lib64/librustc_trans-4e7c5e5c.so
#22 0x00007ffff76dd9d9 in trans::controlflow::trans_block::h40e78d4cabd8c783p2d () from /usr/lib64/librustc_trans-4e7c5e5c.so
#23 0x00007ffff7790e50 in trans::base::trans_closure::h9baffc02e3bf0daf6Au () from /usr/lib64/librustc_trans-4e7c5e5c.so
#24 0x00007ffff76d0a77 in trans::base::trans_fn::h114729a05667bb1dWMu () from /usr/lib64/librustc_trans-4e7c5e5c.so
#25 0x00007ffff76cdc8e in trans::base::trans_item::h7c2b438b1bce4863G8u () from /usr/lib64/librustc_trans-4e7c5e5c.so
#26 0x00007ffff779a408 in trans::base::trans_crate::he69e63600c94fe5506v () from /usr/lib64/librustc_trans-4e7c5e5c.so
#27 0x00007ffff7844945 in driver::driver::phase_4_translate_to_llvm::h81bcee50dff289e18oS () from /usr/lib64/librustc_trans-4e7c5e5c.so
#28 0x00007ffff7834105 in driver::driver::compile_input::h117f94c1b348a398YVR () from /usr/lib64/librustc_trans-4e7c5e5c.so
#29 0x00007ffff78b7cd7 in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#30 0x00007ffff78b62fc in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#31 0x00007ffff76c2f78 in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#32 0x00007ffff76c2e83 in ?? () from /usr/lib64/librustc_trans-4e7c5e5c.so
#33 0x00007ffff7bd6be2 in ?? () from /usr/lib64/libnative-4e7c5e5c.so
#34 0x00007ffff7390fec in ?? () from /usr/lib64/librustrt-4e7c5e5c.so
#35 0x00007ffff7390fd6 in rust_try () from /usr/lib64/librustrt-4e7c5e5c.so
#36 0x00007ffff733f843 in unwind::try::h03ead95328113b2fIZc () from /usr/lib64/librustrt-4e7c5e5c.so
#37 0x00007ffff733f70c in task::Task::run::hed7dc0cf620a0172y5b () from /usr/lib64/librustrt-4e7c5e5c.so
#38 0x00007ffff7bd69e7 in ?? () from /usr/lib64/libnative-4e7c5e5c.so
#39 0x00007ffff7340f35 in ?? () from /usr/lib64/librustrt-4e7c5e5c.so
#40 0x00007ffff1e0e294 in start_thread () from /lib64/libpthread.so.0
#41 0x00007ffff70181ed in clone () from /lib64/libc.so.6

Version

PR #19113 on top of 399ff25

It also fails in the playpen, which has version:

rustc 0.13.0-dev (8ed288edb 2014-11-06 16:52:09 +0000)

I think we're not supposed to use the move keyword with boxed closures?