Broken MIR: generator contains type

[nextzhou]

I tried this code:

#![feature(async_await)]
use futures::executor::ThreadPool;

struct N{}
impl Drop for N {
    fn drop(&mut self) { println!("drop n") }
}

fn main() -> Result<(), std::io::Error> {
    let rc = std::rc::Rc::new(N{});
    ThreadPool::new()?.run(async {
        let mut fs = Vec::new();
        for _ in 0..100000 {
            fs.push(async {rc.clone()})
        }
        for f in fs {
            f.await;
        }
    });
    Ok(())
}

this happened:

error: internal compiler error: src/librustc_mir/transform/generator.rs:540: Broken MIR: generator contains type std::rc::Rc<N> in MIR, but typeck only knows about for<'r, 's, 't0, 't1> {std::vec::Vec<impl core::future::future::Future>, fn(std::vec::Vec<impl core::future::future::Future>) -> <std::vec::Vec<impl core::future::future::Future> as std::iter::IntoIterator>::IntoIter {<std::vec::Vec<impl core::future::future::Future> as std::iter::IntoIterator>::into_iter}, std::vec::IntoIter<impl core::future::future::Future>, impl core::future::future::Future, ()}
  --> src/main.rs:11:34
   |
11 |       ThreadPool::new()?.run(async {
   |  __________________________________^
12 | |         let mut fs = Vec::new();
13 | |         for _ in 0..100000 {
14 | |             fs.push(async {rc.clone()})
...  |
18 | |         }
19 | |     });
   | |_____^

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:573:9

Meta

rustc --version --verbose:

rustc 1.37.0-nightly (5f3656ce9 2019-06-11)
binary: rustc
commit-hash: 5f3656ce9a2212fad872605b7a4ee103a155e9f3
commit-date: 2019-06-11
host: x86_64-unknown-linux-gnu
release: 1.37.0-nightly
LLVM version: 8.0

Backtrace:

stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:47
   3: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:36
   4: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:198
   5: std::panicking::default_hook
             at src/libstd/panicking.rs:212
   6: rustc::util::common::panic_hook
   7: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:479
   8: std::panicking::begin_panic
   9: rustc_errors::Handler::span_bug
  10: rustc::util::bug::opt_span_bug_fmt::{{closure}}
  11: rustc::ty::context::tls::with_opt::{{closure}}
  12: rustc::ty::context::tls::with_context_opt
  13: rustc::ty::context::tls::with_opt
  14: rustc::util::bug::opt_span_bug_fmt
  15: rustc::util::bug::span_bug_fmt
  16: <rustc_mir::transform::generator::StateTransform as rustc_mir::transform::MirPass>::run_pass
  17: rustc_mir::transform::run_passes::{{closure}}
  18: rustc_mir::transform::run_passes
  19: rustc_mir::transform::optimized_mir
  20: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::optimized_mir>::compute
  21: rustc::dep_graph::graph::DepGraph::with_task_impl
  22: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  23: rustc::ty::layout::LayoutCx<rustc::ty::context::TyCtxt>::layout_raw_uncached
  24: rustc::ty::layout::layout_raw
  25: rustc::ty::query::__query_compute::layout_raw
  26: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::layout_raw>::compute
  27: rustc::dep_graph::graph::DepGraph::with_task_impl
  28: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  29: <rustc::ty::layout::LayoutCx<rustc::ty::context::TyCtxt> as rustc_target::abi::LayoutOf>::layout_of
  30: <rustc_mir::transform::const_prop::ConstPropagator as rustc::mir::visit::MutVisitor>::visit_statement
  31: <rustc_mir::transform::const_prop::ConstProp as rustc_mir::transform::MirPass>::run_pass
  32: rustc_mir::transform::run_passes::{{closure}}
  33: rustc_mir::transform::run_passes
  34: rustc_mir::transform::optimized_mir
  35: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::optimized_mir>::compute
  36: rustc::dep_graph::graph::DepGraph::with_task_impl
  37: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  38: rustc_mir::monomorphize::collector::collect_items_rec
  39: rustc_mir::monomorphize::collector::collect_crate_mono_items::{{closure}}
  40: rustc::util::common::time
  41: rustc_mir::monomorphize::collector::collect_crate_mono_items
  42: rustc::util::common::time
  43: rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items
  44: rustc::ty::query::__query_compute::collect_and_partition_mono_items
  45: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::collect_and_partition_mono_items>::compute
  46: rustc::dep_graph::graph::DepGraph::with_task_impl
  47: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  48: rustc_codegen_ssa::base::codegen_crate
  49: <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_utils::codegen_backend::CodegenBackend>::codegen_crate
  50: rustc::util::common::time
  51: rustc_interface::passes::start_codegen
  52: rustc::ty::context::tls::enter_global
  53: rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}}
  54: rustc_interface::passes::create_global_ctxt::{{closure}}
  55: rustc_interface::passes::BoxedGlobalCtxt::enter
  56: rustc_interface::queries::Query<T>::compute
  57: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::ongoing_codegen
  58: rustc_interface::interface::run_compiler_in_existing_thread_pool
  59: std::thread::local::LocalKey<T>::with
  60: scoped_tls::ScopedKey<T>::set
  61: syntax::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
query stack during panic:
#0 [optimized_mir] processing `main::{{closure}}#0`
#1 [layout_raw] computing layout of `[static generator@src/main.rs:11:34: 19:6 rc:&std::rc::Rc<N> for<'r, 's, 't0, 't1> {std::vec::Vec<impl core::future::future::Future>, fn(std::vec::Vec<impl core::future::future::Future>) -> <std::vec::Vec<impl core::future::future::Future> as std::iter::IntoIterator>::IntoIter {<std::vec::Vec<impl core::future::future::Future> as std::iter::IntoIterator>::into_iter}, std::vec::IntoIter<impl core::future::future::Future>, impl core::future::future::Future, ()}]`
#2 [optimized_mir] processing `main`
#3 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack
error: aborting due to previous error

[mati865]

Duplicate of #61442