Issue 1:
[jakob@aspire hyper]$ RUST_BACKTRACE=1 cargo build
Compiling hyper v0.0.1 (file:///home/jakob/devel/hyper)
<std macros>:3:24: 119:30 error: type `http::HttpWriter<std::io::buffered::BufferedWriter<Box<net::NetworkStream+Send>>>` cannot be dereferenced
<std macros>:3 let dst = &mut *$dst;
<std macros>:4 format_args!(|args| { dst.write_fmt(args) }, $($arg)*)
<std macros>:5 })
<std macros>:6 )
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'index out of bounds: the len is 6 but the index is 6', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/libsyntax/lib.rs:1

stack backtrace:
1: 0x7f86a65479c0 - rt::backtrace::imp::write::h7fe8534f465d0e09y9s
2: 0x7f86a654ab60 - failure::on_fail::h3fe2ecde6aab0bb8rwt
3: 0x7f86a6d07c80 - unwind::begin_unwind_inner::he6bc2073d4eb582enbd
4: 0x7f86a6d07900 - unwind::begin_unwind_fmt::h305b4b28825355b2y8c
5: 0x7f86a6d078c0 - rust_begin_unwind
6: 0x7f86a6d4da70 - panicking::panic_fmt::h9d03fcf6b4c3f8e10Nl
7: 0x7f86a6d52e60 - panicking::panic_bounds_check::h5c6357fea6530f04yMl
8: 0x7f86a43bb130 - codemap::FileMap::get_line::h8bd7cfe56e6cfd5e1aF
9: 0x7f86a43e99b0 - diagnostic::emit::h2322127ddc0c36debCG
10: 0x7f86a43e63d0 - diagnostic::EmitterWriter.Emitter::emit::hb9a4d5c26c04e1df0xG
11: 0x7f86a43e4c50 - diagnostic::Handler::emit::ha390aea82acc4940kfG
12: 0x7f86a43b7910 - diagnostic::SpanHandler::span_err::h83b27707d23c7bfej3F
13: 0x7f86a57b5720 - middle::typeck::infer::InferCtxt<'a, 'tcx>::type_error_message_str_with_expected::h72941615d6be270289E
14: 0x7f86a56c1840 - middle::typeck::infer::InferCtxt<'a, 'tcx>::type_error_message::h3e78576a7aeba36csfF
15: 0x7f86a56caf70 - middle::typeck::check::check_expr_with_unifier::h23742768f253d831DLl
16: 0x7f86a56caf70 - middle::typeck::check::check_expr_with_unifier::h23742768f253d831DLl
17: 0x7f86a573fc40 - middle::typeck::check::check_decl_local::h24893462a5fe4409xSn
18: 0x7f86a573fe00 - middle::typeck::check::check_stmt::h1ca15bfe8a7d5a87xUn
19: 0x7f86a5679d90 - middle::typeck::check::check_block_with_expected::heebc1a2b04a42760MYn
20: 0x7f86a56caf70 - middle::typeck::check::check_expr_with_unifier::h23742768f253d831DLl
21: 0x7f86a55f6100 - middle::typeck::check::_match::check_match::h2c871678897b201eeA8
22: 0x7f86a56caf70 - middle::typeck::check::check_expr_with_unifier::h23742768f253d831DLl
23: 0x7f86a5679d90 - middle::typeck::check::check_block_with_expected::heebc1a2b04a42760MYn
24: 0x7f86a56caf70 - middle::typeck::check::check_expr_with_unifier::h23742768f253d831DLl
25: 0x7f86a573fe00 - middle::typeck::check::check_stmt::h1ca15bfe8a7d5a87xUn
26: 0x7f86a5679d90 - middle::typeck::check::check_block_with_expected::heebc1a2b04a42760MYn
27: 0x7f86a5675810 - middle::typeck::check::check_fn::hd39b1b6b62f22c3fici
28: 0x7f86a5675530 - middle::typeck::check::check_bare_fn::h779ff7b2db70ca5bn1h
29: 0x7f86a567cda0 - middle::typeck::check::check_method_body::h6418d5a11969c3d7nwi
30: 0x7f86a5671310 - middle::typeck::check::check_item::hde22067b8b575546vli
31: 0x7f86a5674e60 - visit::walk_mod::h974639367282189498
32: 0x7f86a5674e60 - visit::walk_mod::h974639367282189498
33: 0x7f86a56751c0 - middle::typeck::check::check_item_types::h7118271db2ab8ea8x0h
34: 0x7f86a5a61e10 - util::common::time::h4997555828079517418
35: 0x7f86a5a61020 - middle::typeck::check_crate::h0949dffd97487b5ejVL
36: 0x7f86a720ba10 - driver::driver::phase_3_run_analysis_passes::h7f3610cf195b4c3abfS
37: 0x7f86a7200830 - driver::driver::compile_input::h13734d451479d6e7VVR
38: 0x7f86a72857b0 - driver::run_compiler::h0a1cb9376c105f68pUT
39: 0x7f86a72856a0 - driver::run::closure.59745
40: 0x7f86a7091ee0 - task::TaskBuilder<S>::try_future::closure.39051
41: 0x7f86a7091cd0 - task::TaskBuilder<S>::spawn_internal::closure.39022
42: 0x7f86a75a5b90 - task::NativeSpawner.Spawner::spawn::closure.2472
43: 0x7f86a6d604c0 - rust_try_inner
44: 0x7f86a6d604b0 - rust_try
45: 0x7f86a6d055e0 - unwind::try::h7c27f4e149aed3f2IZc
46: 0x7f86a6d05470 - task::Task::run::h75863ac7ddab20c0y5b
47: 0x7f86a75a58d0 - task::NativeSpawner.Spawner::spawn::closure.2398
48: 0x7f86a6d06c90 - thread::thread_start::h7822af80b22f729bEqc
49: 0x7f86a15d0460 - start_thread
50: 0x7f86a69db749 - clone
51: 0x0 - <unknown>

Could not compile `hyper`.

[jakob@aspire hyper]$ rustc --version=verbose
rustc 0.13.0-nightly (399ff259e 2014-11-20 00:27:07 +0000)
binary: rustc
commit-hash: 399ff259e18c1061aa4ea60856fcecb486d36624
commit-date: 2014-11-20 00:27:07 +0000
host: x86_64-unknown-linux-gnu
release: 0.13.0-nightly

To reproduce:

Clone https://github.com/jgillich/hyper/tree/fmt

cargo build

Issue 2:
STR

use std::fmt::Show;
use std::io::PipeStream;

struct Program {
stdin: PipeStream,
}

impl Program {
fn send<T: Show>(&mut self, line: T) -> &mut Program {
// OK
//match writeln!(&mut self.stdin, "{}", line) {
// ICE
match writeln!(self.stdin, "{}", line) {
Err(_) => panic!(),
Ok(_) => self,
}
}
}

fn main() {}

Output

task 'rustc' panicked at 'index out of bounds: the len is 6 but the index is 6', /var/tmp/paludis/build/dev-lang-rust-scm/work/rust-scm/src/libsyntax/lib.rs:1

stack backtrace:
1: 0x7f7ac0e18a30 - rt::backtrace::imp::write::h2b9052e6d9bc7115y9s
2: 0x7f7ac0e1bbd0 - <unknown>
3: 0x7f7ac15bdea0 - unwind::begin_unwind_inner::h045530faf4b26040nbd
4: 0x7f7ac15bdb20 - unwind::begin_unwind_fmt::hbb3cb48652ded377y8c
5: 0x7f7ac15bdae0 - rust_begin_unwind
6: 0x7f7ac15fa590 - panicking::panic_fmt::hc3aa7deba1f6ed540Nl
7: 0x7f7ac15ff980 - panicking::panic_bounds_check::h40d1ef7dd63df707yMl
8: 0x7f7abec8bba0 - codemap::FileMap::get_line::haca5f2812f60e330m4E
9: 0x7f7abecba5c0 - <unknown>
10: 0x7f7abecb6fe0 - diagnostic::EmitterWriter.Emitter::emit::h8944016a574210b0lrG
11: 0x7f7abecb5860 - diagnostic::Handler::emit::hef6d94e096dac3f1F8F
12: 0x7f7abec88380 - diagnostic::SpanHandler::span_err::he4174115bd82cc5fEWF
13: 0x7f7ac00875d0 - middle::typeck::infer::InferCtxt<'a, 'tcx>::type_error_message_str_with_expected::h0350e4ffa557951e6rF
14: 0x7f7abffd1cc0 - middle::typeck::infer::InferCtxt<'a, 'tcx>::type_error_message::h216c2650f9e1a343qxF
15: 0x7f7abffdb420 - <unknown>
16: 0x7f7abffdb420 - <unknown>
17: 0x7f7ac0011ca0 - middle::typeck::check::check_decl_local::hba8b231eaafb10e9vao
18: 0x7f7ac0011e60 - middle::typeck::check::check_stmt::ha5de4679bb4bc747vco
19: 0x7f7abff93bc0 - <unknown>
20: 0x7f7abffdb420 - <unknown>
21: 0x7f7abfec6f70 - middle::typeck::check::_match::check_match::h4e3330be3e1c359eyz8
22: 0x7f7abffdb420 - <unknown>
23: 0x7f7abff93bc0 - <unknown>
24: 0x7f7abff6b9b0 - <unknown>
25: 0x7f7abff904c0 - <unknown>
26: 0x7f7abff96bd0 - <unknown>
27: 0x7f7abff8c2b0 - middle::typeck::check::check_item::hd604129538ea4d11VQi
28: 0x7f7abff90150 - middle::typeck::check::check_item_types::h1a3e4c15e3ead8aeXvi
29: 0x7f7ac0333c60 - <unknown>
30: 0x7f7ac0332e70 - middle::typeck::check_crate::he5192d314e6838dfhdM
31: 0x7f7ac1ab8bf0 - driver::driver::phase_3_run_analysis_passes::he238813c217c3b94efS
32: 0x7f7ac1aada10 - driver::driver::compile_input::h117f94c1b348a398YVR
33: 0x7f7ac1b323d0 - <unknown>
34: 0x7f7ac1b322c0 - <unknown>
35: 0x7f7ac193ef30 - <unknown>
36: 0x7f7ac193ed20 - <unknown>
37: 0x7f7ac1e52b70 - <unknown>
38: 0x7f7ac160cfe0 - <unknown>
39: 0x7f7ac160cfd0 - rust_try
40: 0x7f7ac15bb800 - unwind::try::h03ead95328113b2fIZc
41: 0x7f7ac15bb690 - task::Task::run::hed7dc0cf620a0172y5b
42: 0x7f7ac1e528b0 - <unknown>
43: 0x7f7ac15bceb0 - <unknown>
44: 0x7f7abc08a1d0 - start_thread
45: 0x7f7ac12941b9 - clone
46: 0x0 - <unknown>

Version

Equivalent code was compiling with:

rustc 0.13.0-nightly (e09d98603 2014-11-18 23:51:43 +0000)

But now it's ICEing on: 1d81776

I think #19040 may have introduced the ICE.

cc @alexcrichton