Lowered command panics with auto trait

[jrr45]

Using the interactive commands, creating the program

#[auto] trait Send { }
struct SomeStruct<T> { }

then calling "lowered" causes chalk to panic. The same does not seem to happen by creating a test and using "lowering_success" with the same program.

[detrumi]

That's this assertion in Binders<T>::substitute() https://github.com/rust-lang/chalk/blob/60bbf5408cb6050ef62c98fb75400f95f664ccb2/chalk-ir/src/lib.rs#L2249

Backtrace

thread 'main' panicked at 'assertion failed: `(left == right)`
  left: `1`,
 right: `0`', /home/wilco/p/rust/chalk/chalk-ir/src/lib.rs:2249:9
stack backtrace:
   0: rust_begin_unwind
             at /rustc/bb8c2f41174caceec00c28bc6c5c20ae9f9a175c/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/bb8c2f41174caceec00c28bc6c5c20ae9f9a175c/library/core/src/panicking.rs:142:14
   2: core::panicking::assert_failed_inner
   3: core::panicking::assert_failed
             at /rustc/bb8c2f41174caceec00c28bc6c5c20ae9f9a175c/library/core/src/panicking.rs:181:5
   4: chalk_ir::Binders<T>::substitute
             at ./chalk-ir/src/lib.rs:2249:9
   5: chalk_solve::clauses::constituent_types
             at ./chalk-solve/src/clauses.rs:33:35
   6: chalk_solve::clauses::push_auto_trait_impls
             at ./chalk-solve/src/clauses.rs:208:30
   7: chalk_integration::query::environment
             at ./chalk-integration/src/query.rs:229:13
   8: <chalk_integration::query::EnvironmentQuery as salsa::plumbing::QueryFunction>::execute
             at ./chalk-integration/src/query.rs:51:8
   9: salsa::derived::slot::Slot<Q,MP>::read_upgrade::{{closure}}
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/salsa-0.16.1/src/derived/slot.rs:218:13
  10: salsa::runtime::Runtime::execute_query_implementation
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/salsa-0.16.1/src/runtime.rs:330:21
  11: salsa::derived::slot::Slot<Q,MP>::read_upgrade
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/salsa-0.16.1/src/derived/slot.rs:215:26
  12: salsa::derived::slot::Slot<Q,MP>::read
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/salsa-0.16.1/src/derived/slot.rs:148:9
  13: <salsa::derived::DerivedStorage<Q,MP> as salsa::plumbing::QueryStorageOps<Q>>::try_fetch
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/salsa-0.16.1/src/derived.rs:170:13
  14: salsa::QueryTable<Q>::try_get
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/salsa-0.16.1/src/lib.rs:494:9
  15: salsa::QueryTable<Q>::get
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/salsa-0.16.1/src/lib.rs:490:9
  16: <DB as chalk_integration::query::LoweringDatabase>::environment::__shim
             at ./chalk-integration/src/query.rs:27:1
  17: <DB as chalk_integration::query::LoweringDatabase>::environment
             at ./chalk-integration/src/query.rs:27:1
  18: chalk::process::{{closure}}
             at ./src/main.rs:245:48
  19: chalk_integration::db::ChalkDatabase::with_program::{{closure}}
             at ./chalk-integration/src/db.rs:43:46
  20: chalk_integration::tls::set_current_program::{{closure}}
             at ./chalk-integration/src/tls.rs:172:17
  21: std::thread::local::LocalKey<T>::try_with
             at /rustc/bb8c2f41174caceec00c28bc6c5c20ae9f9a175c/library/std/src/thread/local.rs:445:16
  22: std::thread::local::LocalKey<T>::with
             at /rustc/bb8c2f41174caceec00c28bc6c5c20ae9f9a175c/library/std/src/thread/local.rs:421:9
  23: chalk_integration::tls::set_current_program
             at ./chalk-integration/src/tls.rs:170:5
  24: chalk_integration::db::ChalkDatabase::with_program
             at ./chalk-integration/src/db.rs:43:9
  25: chalk::process
             at ./src/main.rs:239:9
  26: chalk::run::{{closure}}
             at ./src/main.rs:138:29
  27: chalk::readline_loop
             at ./src/main.rs:181:17
  28: chalk::run
             at ./src/main.rs:137:9
  29: chalk::main::{{closure}}
             at ./src/main.rs:313:36
  30: tracing_core::dispatcher::with_default
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/tracing-core-0.1.21/src/dispatcher.rs:228:5
  31: tracing::subscriber::with_default
             at /home/wilco/.cargo/registry/src/github.com-1ecc6299db9ec823/tracing-0.1.29/src/subscriber.rs:24:5
  32: chalk_solve::logging::with_tracing_logs
             at ./chalk-solve/src/logging.rs:11:5
  33: chalk::main
             at ./src/main.rs:312:5
  34: core::ops::function::FnOnce::call_once
             at /rustc/bb8c2f41174caceec00c28bc6c5c20ae9f9a175c/library/core/src/ops/function.rs:248:5

Also happens when you load the program from a file.