1.40.0 ICE while reporting ICE

[TheBlueMatt]

rustc+cargo 1.40.0 Debian testing packages report the following ICE (which does not go away after a cargo clean):

It can be reproduced by trying to build https://github.com/TheBlueMatt/rust-lightning-bitcoinrpc/tree/2020-02-ice-demo against https://github.com/TheBlueMatt/rust-lightning/tree/2020-02-rustc-ice.

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:378:21
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.

error: internal compiler error: unexpected panic

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.40.0 running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C incremental --crate-type bin

note: some of the compiler flags provided by cargo are hidden

error: could not compile `rust-lightning-bitcoinrpc`.

To learn more, run the command again with --verbose.
matt@cdev1:~/Documents/Projects/Bitcoin/rust-lightning-bitcoinrpc$ RUST_BACKTRACE=1 cargo build && RUST_BACKTRACE=1 ./target/debug/rust-lightning-bitcoinrpc __cookie__:f70ead21e4528ac6e74c8e182297a2b5f3041522ee55481175d4413ae552ab56@69.59.18.207:18332 `pwd`/toktest/
   Compiling rust-lightning-bitcoinrpc v0.0.1 (/home/matt/Documents/Projects/Bitcoin/rust-lightning-bitcoinrpc)
thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:378:21
stack backtrace:
   0: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
   1: core::fmt::write
   2: <unknown>
   3: <unknown>
   4: <unknown>
   5: rustc_driver::report_ice
   6: <alloc::boxed::Box<F> as core::ops::function::Fn<A>>::call
             at /usr/src/rustc-1.40.0/src/liballoc/boxed.rs:956
   7: proc_macro::bridge::client::<impl proc_macro::bridge::Bridge>::enter::{{closure}}::{{closure}}
             at /usr/src/rustc-1.40.0/src/libproc_macro/bridge/client.rs:305
   8: std::panicking::rust_panic_with_hook
   9: <unknown>
  10: rust_begin_unwind
  11: core::panicking::panic_fmt
  12: core::panicking::panic
  13: <unknown>
  14: <unknown>
  15: <unknown>
  16: <unknown>
  17: <unknown>
  18: <unknown>
  19: <unknown>
  20: <unknown>
  21: <unknown>
  22: rustc::traits::error_reporting::<impl rustc::infer::InferCtxt>::report_selection_error
  23: rustc::traits::error_reporting::<impl rustc::infer::InferCtxt>::report_fulfillment_errors
  24: <unknown>
  25: <unknown>
  26: <unknown>
  27: <unknown>
  28: <unknown>
  29: <unknown>
  30: <unknown>
  31: <unknown>
  32: <unknown>
  33: <unknown>
  34: <unknown>
  35: rustc_typeck::collect::checked_type_of
  36: <unknown>
  37: <unknown>
  38: <unknown>
  39: <unknown>
  40: <unknown>
  41: <unknown>
  42: <unknown>
  43: <unknown>
  44: <unknown>
  45: <rustc_typeck::collect::CollectItemTypesVisitor as rustc::hir::intravisit::Visitor>::visit_item
  46: <unknown>
  47: <unknown>
  48: <unknown>
  49: <unknown>
  50: <unknown>
  51: <unknown>
  52: <unknown>
  53: <unknown>
  54: <unknown>
  55: rustc_typeck::check_crate
  56: <unknown>
  57: <unknown>
  58: <unknown>
  59: <unknown>
  60: <unknown>
  61: <unknown>
  62: <unknown>
  63: <unknown>
  64: <unknown>
  65: <unknown>
  66: <unknown>
  67: <unknown>
  68: __rust_maybe_catch_panic
  69: <unknown>
  70: <unknown>
  71: <unknown>
  72: <unknown>
  73: start_thread
  74: __clone
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: internal compiler error: unexpected panic

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.40.0 running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C incremental --crate-type bin

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [typeck_tables_of] processing `lightning_net_tokio::Connection::setup_outbound`
#1 [typeck_tables_of] processing `lightning_net_tokio::Connection::setup_outbound::{{closure}}#0`
#2 [typeck_tables_of] processing `main`
#3 [typeck_tables_of] processing `main::{{closure}}#0`
#4 [type_of] processing `main::{{closure}}#0`
#5 [collect_mod_item_types] collecting item types in top-level module
#6 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `rust-lightning-bitcoinrpc`.

To learn more, run the command again with --verbose.

[jonas-schievink]

Can you try this on nightly?

[pnkfelix]

Once the ICEBreakers-CleanupCrew is announced (which I think will be happening very soon), we should advertise this bug on it (at least the reduction to MCVE part of it); see rust-lang/compiler-team#207

[pnkfelix]

triage: P-high for initial investigation (i.e. identifying actual severity), removing nomination.

[pnkfelix]

@rustbot ping icebreakers-cleanup-crew

[rustbot]

Hey Cleanup Crew ICE-breakers! This bug has been identified as a good
"Cleanup ICE-breaking candidate". In case it's useful, here are some
instructions for tackling these sorts of bugs. Maybe take a look?
Thanks! <3

cc @spastorino

[pnkfelix]

Note that when I had a go at building rust-lightning-bitcoinrpc on my Mac laptop, it failed with this message:

error: cannot find attribute `error` in this scope
   --> src/main.rs:253:3
    |
253 | #[error("OSX creatively eats your data, using Lightning on OSX is unsafe")]
    |   ^^^^^

error: aborting due to previous error

error: could not compile `rust-lightning-bitcoinrpc`.

This is due to this line in the source crate:

#[cfg(any(target_os = "macos", target_os = "ios"))]
#[error("OSX creatively eats your data, using Lightning on OSX is unsafe")]
struct ERR {}

So if you are on a Mac laptop, it may or may not be worth your effort to investigate this. (It is probably easy to work around, but I figure I'd let people know up front.)

[TheBlueMatt]

Oops, right, you'll want to just drop that line. It shouldn't have any other effect, its only there due to (at least previously, based on my super-cursory read) libstd calling regular fsync() on OSX, which historically, well, didn't fsync.

[pnkfelix]

I looked at this a bit more.

I see the ICE on stable and beta.

I do not see the ICE on nightly.

On nightly, I instead get the following error:

Click here to see error diagnostics

% cargo +nightly build
warning: unnecessary parentheses around block return value
   --> /private/tmp/rust-lightning/lightning/src/chain/keysinterface.rs:449:3
    |
449 |         (Sha256::from_engine(sha).into_inner())
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
    |
    = note: `#[warn(unused_parens)]` on by default

warning: use of deprecated item 'std::error::Error::description': use the Display impl or to_string()
   --> /private/tmp/rust-lightning/lightning/src/ln/msgs.rs:741:32
    |
741 |             DecodeError::Io(ref e) => e.description(),
    |                                         ^^^^^^^^^^^
    |
    = note: `#[warn(deprecated)]` on by default

warning: use of deprecated item 'std::error::Error::description': use the Display impl or to_string()
   --> /private/tmp/rust-lightning/lightning/src/ln/msgs.rs:747:20
    |
747 |         f.write_str(self.description())
    |                          ^^^^^^^^^^^

warning: field is never read: `logger`
   --> /private/tmp/rust-lightning/lightning/src/chain/chaininterface.rs:303:2
    |
303 |     logger: Arc<Logger>,
    |     ^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default

warning: field is never read: `logger`
   --> /private/tmp/rust-lightning/lightning/src/chain/keysinterface.rs:295:2
    |
295 |     logger: Arc<Logger>,
    |     ^^^^^^^^^^^^^^^^^^^

warning: variant is never constructed: `Watchtower`
   --> /private/tmp/rust-lightning/lightning/src/ln/channelmonitor.rs:351:2
    |
351 |       Watchtower {
    |  _____^
352 | |         revocation_base_key: PublicKey,
353 | |         htlc_base_key: PublicKey,
354 | |     }
    | |_____^

warning: unused import: `lightning::ln::peer_handler::SocketDescriptor as LnSocketTrait`
 --> /private/tmp/rust-lightning/lightning-net-tokio/src/lib.rs:9:5
  |
9 | use lightning::ln::peer_handler::SocketDescriptor as LnSocketTrait;
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: unused `std::result::Result` that must be used
   --> /private/tmp/rust-lightning/lightning-net-tokio/src/lib.rs:174:4
    |
174 |             tokio::spawn(Self::schedule_read(peer_manager, us, reader, receiver)).await;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(unused_must_use)]` on by default
    = note: this `Result` may be an `Err` variant, which should be handled

warning: unused `std::result::Result` that must be used
   --> /private/tmp/rust-lightning/lightning-net-tokio/src/lib.rs:195:4
    |
195 |             tokio::spawn(Self::schedule_read(peer_manager, us, reader, receiver)).await;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: this `Result` may be an `Err` variant, which should be handled

   Compiling rust-lightning-bitcoinrpc v0.0.1 (/private/tmp/rust-lightning-bitcoinrpc)
error[E0277]: `std::sync::MutexGuard<'_, lightning_net_tokio::Connection>` cannot be sent between threads safely
   --> src/main.rs:521:30
    |
521 |                                             join_handles.push(tokio::spawn(async move {
    |                                                               ^^^^^^^^^^^^ `std::sync::MutexGuard<'_, lightning_net_tokio::Connection>` cannot be sent between threads safely
    | 
   ::: /Users/felixklock/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.11/src/task/spawn.rs:123:21
    |
123 |         T: Future + Send + 'static,
    |                     ---- required by this bound in `tokio::task::spawn::spawn`
    |
    = help: within `impl std::future::Future`, the trait `std::marker::Send` is not implemented for `std::sync::MutexGuard<'_, lightning_net_tokio::Connection>`
    = note: required because it appears within the type `for<'r, 's, 't0, 't1, 't2, 't3, 't4, 't5, 't6, 't7, 't8, 't9> {std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, tokio::sync::mpsc::bounded::Sender<()>, secp256k1::key::PublicKey, tokio::net::tcp::stream::TcpStream, tokio::io::split::ReadHalf<tokio::net::tcp::stream::TcpStream>, tokio::sync::mpsc::bounded::Receiver<()>, std::sync::Arc<std::sync::Mutex<lightning_net_tokio::Connection>>, &'r lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>, &'s std::sync::Arc<std::sync::Mutex<lightning_net_tokio::Connection>>, lightning_net_tokio::SocketDescriptor, std::result::Result<std::vec::Vec<u8>, lightning::ln::peer_handler::PeerHandleError>, std::vec::Vec<u8>, &'t0 std::sync::Mutex<lightning_net_tokio::Connection>, std::result::Result<std::sync::MutexGuard<'t1, lightning_net_tokio::Connection>, std::sync::PoisonError<std::sync::MutexGuard<'t2, lightning_net_tokio::Connection>>>, lightning_net_tokio::Connection, std::sync::MutexGuard<'t3, lightning_net_tokio::Connection>, &'t4 mut std::option::Option<tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, std::option::Option<tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, std::option::Option<&'t5 mut tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, &'t6 mut tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>, &'t7 [u8], &'t8 std::vec::Vec<u8>, tokio::io::util::write_all::WriteAll<'t9, tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, (), impl std::future::Future, tokio::task::join::JoinHandle<()>}`
    = note: required because it appears within the type `[static generator@DefId(75:54 ~ lightning_net_tokio[f695]::{{impl}}[0]::setup_outbound[0]::{{closure}}[0]) 0:std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, 1:tokio::sync::mpsc::bounded::Sender<()>, 2:secp256k1::key::PublicKey, 3:tokio::net::tcp::stream::TcpStream for<'r, 's, 't0, 't1, 't2, 't3, 't4, 't5, 't6, 't7, 't8, 't9> {std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, tokio::sync::mpsc::bounded::Sender<()>, secp256k1::key::PublicKey, tokio::net::tcp::stream::TcpStream, tokio::io::split::ReadHalf<tokio::net::tcp::stream::TcpStream>, tokio::sync::mpsc::bounded::Receiver<()>, std::sync::Arc<std::sync::Mutex<lightning_net_tokio::Connection>>, &'r lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>, &'s std::sync::Arc<std::sync::Mutex<lightning_net_tokio::Connection>>, lightning_net_tokio::SocketDescriptor, std::result::Result<std::vec::Vec<u8>, lightning::ln::peer_handler::PeerHandleError>, std::vec::Vec<u8>, &'t0 std::sync::Mutex<lightning_net_tokio::Connection>, std::result::Result<std::sync::MutexGuard<'t1, lightning_net_tokio::Connection>, std::sync::PoisonError<std::sync::MutexGuard<'t2, lightning_net_tokio::Connection>>>, lightning_net_tokio::Connection, std::sync::MutexGuard<'t3, lightning_net_tokio::Connection>, &'t4 mut std::option::Option<tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, std::option::Option<tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, std::option::Option<&'t5 mut tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, &'t6 mut tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>, &'t7 [u8], &'t8 std::vec::Vec<u8>, tokio::io::util::write_all::WriteAll<'t9, tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, (), impl std::future::Future, tokio::task::join::JoinHandle<()>}]`
    = note: required because it appears within the type `std::future::GenFuture<[static generator@DefId(75:54 ~ lightning_net_tokio[f695]::{{impl}}[0]::setup_outbound[0]::{{closure}}[0]) 0:std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, 1:tokio::sync::mpsc::bounded::Sender<()>, 2:secp256k1::key::PublicKey, 3:tokio::net::tcp::stream::TcpStream for<'r, 's, 't0, 't1, 't2, 't3, 't4, 't5, 't6, 't7, 't8, 't9> {std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, tokio::sync::mpsc::bounded::Sender<()>, secp256k1::key::PublicKey, tokio::net::tcp::stream::TcpStream, tokio::io::split::ReadHalf<tokio::net::tcp::stream::TcpStream>, tokio::sync::mpsc::bounded::Receiver<()>, std::sync::Arc<std::sync::Mutex<lightning_net_tokio::Connection>>, &'r lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>, &'s std::sync::Arc<std::sync::Mutex<lightning_net_tokio::Connection>>, lightning_net_tokio::SocketDescriptor, std::result::Result<std::vec::Vec<u8>, lightning::ln::peer_handler::PeerHandleError>, std::vec::Vec<u8>, &'t0 std::sync::Mutex<lightning_net_tokio::Connection>, std::result::Result<std::sync::MutexGuard<'t1, lightning_net_tokio::Connection>, std::sync::PoisonError<std::sync::MutexGuard<'t2, lightning_net_tokio::Connection>>>, lightning_net_tokio::Connection, std::sync::MutexGuard<'t3, lightning_net_tokio::Connection>, &'t4 mut std::option::Option<tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, std::option::Option<tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, std::option::Option<&'t5 mut tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, &'t6 mut tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>, &'t7 [u8], &'t8 std::vec::Vec<u8>, tokio::io::util::write_all::WriteAll<'t9, tokio::io::split::WriteHalf<tokio::net::tcp::stream::TcpStream>>, (), impl std::future::Future, tokio::task::join::JoinHandle<()>}]>`
    = note: required because it appears within the type `impl std::future::Future`
    = note: required because it appears within the type `impl std::future::Future`
    = note: required because it appears within the type `{std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, tokio::sync::mpsc::bounded::Sender<()>, secp256k1::key::PublicKey, std::net::TcpStream, std::result::Result<tokio::net::tcp::stream::TcpStream, std::io::Error>, tokio::net::tcp::stream::TcpStream, impl std::future::Future, ()}`
    = note: required because it appears within the type `[static generator@src/main.rs:521:54: 524:13 peer_manager:std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, event_notify:tokio::sync::mpsc::bounded::Sender<()>, pk:secp256k1::key::PublicKey, stream:std::net::TcpStream {std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, tokio::sync::mpsc::bounded::Sender<()>, secp256k1::key::PublicKey, std::net::TcpStream, std::result::Result<tokio::net::tcp::stream::TcpStream, std::io::Error>, tokio::net::tcp::stream::TcpStream, impl std::future::Future, ()}]`
    = note: required because it appears within the type `std::future::GenFuture<[static generator@src/main.rs:521:54: 524:13 peer_manager:std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, event_notify:tokio::sync::mpsc::bounded::Sender<()>, pk:secp256k1::key::PublicKey, stream:std::net::TcpStream {std::sync::Arc<lightning::ln::peer_handler::PeerManager<lightning_net_tokio::SocketDescriptor, std::sync::Arc<lightning::ln::channelmanager::ChannelManager<lightning::chain::keysinterface::InMemoryChannelKeys, std::sync::Arc<ChannelMonitor>>>>>, tokio::sync::mpsc::bounded::Sender<()>, secp256k1::key::PublicKey, std::net::TcpStream, std::result::Result<tokio::net::tcp::stream::TcpStream, std::io::Error>, tokio::net::tcp::stream::TcpStream, impl std::future::Future, ()}]>`
    = note: required because it appears within the type `impl std::future::Future`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.
error: could not compile `rust-lightning-bitcoinrpc`.

To learn more, run the command again with --verbose.