Issue 1:
sample session:

$ rusti
WARNING: The Rust REPL is experimental and may be
unstable. If you encounter problems, please use the
compiler instead.
rusti> fn f() {}
()
rusti> fn f() {}
()
rusti> 42;
<anon>:35:0: 35:10 error: duplicate definition of value f
<anon>:35 fn f() { }
^~~~~~~~~~
<anon>:33:0: 33:10 note: first definition of value f here:
<anon>:33 fn f() { }
^~~~~~~~~~
error: aborting due to previous error
rust: task failed at 'explicit failure', /home/ben/code/repos/rust/src/libsyntax/diagnostic.rs:99

Issue 2:
See comment below: #13655 (comment).

old report

I tried running it in the debugger, but couldn't get gdb to find "rust_fail" for a breakpoint. I also didn't check whether this is a duplicate, sorry.

$ rustc -v

rustc 0.11-pre-nightly (e332287 2014-04-16 00:56:30 -0700)

host: x86_64-unknown-linux-gnu

rustc server.rs
schooner/log.rs:202:13: 202:23 error: mismatched types: expected `std::result::Result<~str,std::io::IoError>` but found `std::option::Option<<generic #264>>` (expected enum std::result::Result but found enum std::option::Option)
schooner/log.rs:202 Some(line) => {
^~~~~~~~~~
schooner/log.rs:210:13: 210:17 error: mismatched types: expected `std::result::Result<~str,std::io::IoError>` but found `std::option::Option<<generic #265>>` (expected enum std::result::Result but found enum std::option::Option)
schooner/log.rs:210 None => () // return Err(format!("Problem while reading in log file: {}", path.display().to_str()))
^~~~
error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug.
note: we would appreciate a bug report: http://static.rust-lang.org/doc/master/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' failed at 'index out of bounds: the len is 0 but the index is 0', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/librustc/lib.rs:1
stack backtrace:
1: 0x2ae4d244bf10 - rt::backtrace::imp::write::hb4d14c641715212670a::v0.11.pre
2: 0x2ae4d23ad460 - rt::unwind::begin_unwind_inner::hb6257486a54a301cABa::v0.11.pre
3: 0x2ae4d23ad3d0 - rt::unwind::begin_unwind::h10a9dcad1e815882aBa::v0.11.pre
4: 0x2ae4d244bb20 - rt::unwind::begin_unwind_raw::h18b61474055627a8Jya::v0.11.pre
5: 0x2ae4d23ac700 - rt::unwind::fail_::hc606fb5e7f153625nwa::v0.11.pre
6: 0x2ae4d244bb90 - rt::unwind::fail_bounds_check::closure.40261
7: 0x2ae4d23ae630 - rt::unwind::fail_bounds_check::hc426cbe6f6d8fda9Kwa::v0.11.pre
8: 0x2ae4d0082160 - middle::typeck::check::method::LookupContext$LT$$x27a$GT$::push_bound_candidates::closure.66419
9: 0x2ae4d0081060 - middle::typeck::check::autoderef::h3b3cd92df88ba880fO8::v0.11.pre
10: 0x2ae4d007dda0 - middle::typeck::check::method::LookupContext$LT$$x27a$GT$::push_bound_candidates::hc19431f1eb875546Sy5::v0.11.pre
11: 0x2ae4d007df30 - middle::typeck::check::method::lookup_in_trait::h66356e4f09bb4e3dGh5::v0.11.pre
12: 0x2ae4d007e930 - middle::typeck::check::try_overloaded_deref::h6c4b3c92b2204307bS8::v0.11.pre
13: 0x2ae4d0081060 - middle::typeck::check::autoderef::h3b3cd92df88ba880fO8::v0.11.pre
14: 0x2ae4d007c360 - middle::typeck::check::method::lookup::h2bab3026e2c612cbKa5::v0.11.pre
15: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
16: 0x2ae4d00bed70 - middle::typeck::check::check_expr_with_unifier::check_argument_types::hdf195254fb9ad91aqq9::v0.11.pre
17: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
18: 0x2ae4d001ec70 - middle::typeck::check::_match::check_match::h27f8e9c536cc6bd3dzZ::v0.11.pre
19: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
20: 0x2ae4d00978e0 - middle::typeck::check::check_block_with_expected::h3838f44d28bed00bJGb::v0.11.pre
21: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
22: 0x2ae4d001ec70 - middle::typeck::check::_match::check_match::h27f8e9c536cc6bd3dzZ::v0.11.pre
23: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
24: 0x2ae4d00978e0 - middle::typeck::check::check_block_with_expected::h3838f44d28bed00bJGb::v0.11.pre
25: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
26: 0x2ae4d001ec70 - middle::typeck::check::_match::check_match::h27f8e9c536cc6bd3dzZ::v0.11.pre
27: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
28: 0x2ae4d00978e0 - middle::typeck::check::check_block_with_expected::h3838f44d28bed00bJGb::v0.11.pre
29: 0x2ae4d00c03a0 - middle::typeck::check::check_block_no_value::hd954ad05ca60716aFFb::v0.11.pre
30: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
31: 0x2ae4d001ec70 - middle::typeck::check::_match::check_match::h27f8e9c536cc6bd3dzZ::v0.11.pre
32: 0x2ae4d00b4fe0 - middle::typeck::check::check_expr_with_unifier::he8b805180753f0ebom9::v0.11.pre
33: 0x2ae4d00978e0 - middle::typeck::check::check_block_with_expected::h3838f44d28bed00bJGb::v0.11.pre
34: 0x2ae4d0093020 - middle::typeck::check::check_fn::h9d9a07999182adc5Zp7::v0.11.pre
35: 0x2ae4d0092dc0 - middle::typeck::check::check_bare_fn::hb6bc5891dd566922Rf7::v0.11.pre
36: 0x2ae4d008e130 - middle::typeck::check::check_item::hb61a6cf0c634001eZx7::v0.11.pre
37: 0x2ae4d008fbb0 - visit::walk_item::h820b10196031a87d1xw::v0.11.pre
38: 0x2ae4d008fbb0 - visit::walk_item::h820b10196031a87d1xw::v0.11.pre
39: 0x2ae4d0092ca0 - middle::typeck::check::check_item_types::h81b2805d49e06382rf7::v0.11.pre
40: 0x2ae4d01d32c0 - util::common::time::h104026deb384af9cxFg::v0.11.pre
41: 0x2ae4d01d1c90 - middle::typeck::check_crate::hff5b61383c42166fV7t::v0.11.pre
42: 0x2ae4d06063f0 - driver::driver::phase_3_run_analysis_passes::h268420b55d9aba34Xre::v0.11.pre
43: 0x2ae4d060ce00 - driver::driver::compile_input::h3ccf917b299cf56eSQe::v0.11.pre
44: 0x2ae4d06311e0 - run_compiler::he183fbc68c036254gpm::v0.11.pre
45: 0x2ae4d06488e0 - main_args::closure.91933
46: 0x2ae4d0647210 - monitor::closure.91818
47: 0x2ae4d0642af0 - task::TaskBuilder::try::closure.91584
48: 0x2ae4cf8c5fa0 - task::spawn_opts::closure.7973
49: 0x2ae4d2446f40 - rt::task::Task::run::closure.40163
50: 0x2ae4d2452aa0 - rust_try
51: 0x2ae4d2446d80 - rt::task::Task::run::hf191250bb000025bBr8::v0.11.pre
52: 0x2ae4cf8c5d70 - task::spawn_opts::closure.7946
53: 0x2ae4d244aa50 - rt::thread::thread_start::h7631e63c8ba8fa17g68::v0.11.pre
54: 0x2ae4d2e76ea0 - start_thread
55: 0x2ae4d2ba1999 - __clone
56: 0x0 - <unknown>