Change:
Sysroot has been compiled using to get set. Otherwise it is hard to guess a defid with encoded mir, now it is just taking the first exported symbol from:
I used to read the mir.
I think these are and printed as . If so it would be less confusing if the debug impl of would say or something like that instead.
I'm unsure how to reproduce the environment to reproduce this bug. It's easy to adjust the debug printing for , but without a test for that I'm not sure how to test it

Discussion:
} fn span_to_string(&self, sp: Span, prefer_local: bool) -> String { <del> if self.files.borrow().source_files.is_empty() && sp.is_dummy() { </del> <ins> if self.files.borrow().source_files.is_empty() || sp.is_dummy() { </ins> return "no-location".to_string(); }

bb8 (cleanup): { StorageDead(_10);                // scope 2 at $DIR/generator-storage-dead-unwind.rs:27:15: 27:16 StorageDead(_9);                 // scope 2 at $DIR/generator-storage-dead-unwind.rs:27:16: 27:17 <del> goto -> bb10;                    // scope 2 at $DIR/generator-storage-dead-unwind.rs:1:1: 1:1 </del> <ins> goto -> bb10;                    // scope 2 at no-location </ins> } bb9 (cleanup): { StorageDead(_8);                 // scope 2 at $DIR/generator-storage-dead-unwind.rs:26:15: 26:16 StorageDead(_7);                 // scope 2 at $DIR/generator-storage-dead-unwind.rs:26:16: 26:17 <del> goto -> bb10;                    // scope 2 at $DIR/generator-storage-dead-unwind.rs:1:1: 1:1 </del> <ins> goto -> bb10;                    // scope 2 at no-location </ins> } bb10 (cleanup): {

_6 = const 1_i32;                // scope 0 at $DIR/loop_test.rs:14:17: 14:18 FakeRead(ForLet(None), _6);      // scope 0 at $DIR/loop_test.rs:14:13: 14:14 StorageDead(_6);                 // scope 0 at $DIR/loop_test.rs:16:5: 16:6 <del> goto -> bb3;                     // scope 0 at $DIR/loop_test.rs:1:1: 1:1 </del> <ins> goto -> bb3;                     // scope 0 at no-location </ins> } bb5 (cleanup): {

_0 = const 3_i32;                // scope 0 at $DIR/match-arm-scopes.rs:15:59: 15:60 StorageDead(_10);                // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73 StorageDead(_9);                 // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78 <del> -         goto -> bb23;                    // scope 0 at $DIR/match-arm-scopes.rs:1:1: 1:1 +         goto -> bb20;                    // scope 0 at $DIR/match-arm-scopes.rs:1:1: 1:1 </del> <ins> -         goto -> bb23;                    // scope 0 at no-location +         goto -> bb20;                    // scope 0 at no-location </ins> } -     bb10: {

_0 = const 3_i32;                // scope 0 at $DIR/match-arm-scopes.rs:15:59: 15:60 StorageDead(_13);                // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73 StorageDead(_12);                // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78 <del> -         goto -> bb23;                    // scope 0 at $DIR/match-arm-scopes.rs:1:1: 1:1 +         goto -> bb20;                    // scope 0 at $DIR/match-arm-scopes.rs:1:1: 1:1 </del> <ins> -         goto -> bb23;                    // scope 0 at no-location +         goto -> bb20;                    // scope 0 at no-location </ins> } -     bb15: {

bb4: { StorageDead(_4);                 // scope 0 at $DIR/while-storage.rs:13:9: 13:10 <del> goto -> bb6;                     // scope 0 at $DIR/while-storage.rs:1:1: 1:1 </del> <ins> goto -> bb6;                     // scope 0 at no-location </ins> } bb5: {