Print thread ID in panic message if thread name is unknown

`panic!` does not print any identifying information for threads that are
unnamed. However, in many cases, the thread ID can be determined.

This changes the panic message from something like this:

    thread '<unnamed>' panicked at src/main.rs:3:5:
    explicit panic

To something like this:

    thread '<unnamed>' (0xff9bf) panicked at src/main.rs:3:5:
    explicit panic

Stack overflow messages are updated as well.

This change applies to both named and unnamed threads. The ID printed is
the OS integer thread ID rather than the Rust thread ID, which should
also be what debuggers print.

37 files changed, 65 insertions, 58 deletions

diff --git a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.stderr b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.stderr
index 9e6abf219f1..afabb8572bd 100644
--- a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.stderr
+++ b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind1.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/function_calls/exported_symbol_bad_unwind1.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/function_calls/exported_symbol_bad_unwind1.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.both.stderr b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.both.stderr
index 14b3be02a79..1246ad5a713 100644
--- a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.both.stderr
+++ b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.both.stderr
@@ -1,10 +1,10 @@
 
-thread 'main' panicked at tests/fail/function_calls/exported_symbol_bad_unwind2.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/function_calls/exported_symbol_bad_unwind2.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'main' panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
+thread 'main' ($TID) panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
 panic in a function that cannot unwind
 stack backtrace:
 thread caused non-unwinding panic. aborting.
diff --git a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.definition.stderr b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.definition.stderr
index 14b3be02a79..1246ad5a713 100644
--- a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.definition.stderr
+++ b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.definition.stderr
@@ -1,10 +1,10 @@
 
-thread 'main' panicked at tests/fail/function_calls/exported_symbol_bad_unwind2.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/function_calls/exported_symbol_bad_unwind2.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'main' panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
+thread 'main' ($TID) panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
 panic in a function that cannot unwind
 stack backtrace:
 thread caused non-unwinding panic. aborting.
diff --git a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.extern_block.stderr b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.extern_block.stderr
index 5a3d5b4a5eb..e755b262474 100644
--- a/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.extern_block.stderr
+++ b/src/tools/miri/tests/fail/function_calls/exported_symbol_bad_unwind2.extern_block.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/function_calls/exported_symbol_bad_unwind2.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/function_calls/exported_symbol_bad_unwind2.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/fail/function_calls/return_pointer_on_unwind.stderr b/src/tools/miri/tests/fail/function_calls/return_pointer_on_unwind.stderr
index 93720ca7d27..77dc2c61e26 100644
--- a/src/tools/miri/tests/fail/function_calls/return_pointer_on_unwind.stderr
+++ b/src/tools/miri/tests/fail/function_calls/return_pointer_on_unwind.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/function_calls/return_pointer_on_unwind.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/function_calls/return_pointer_on_unwind.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/fail/panic/abort_unwind.stderr b/src/tools/miri/tests/fail/panic/abort_unwind.stderr
index 35052f37dfc..09f19a6e494 100644
--- a/src/tools/miri/tests/fail/panic/abort_unwind.stderr
+++ b/src/tools/miri/tests/fail/panic/abort_unwind.stderr
@@ -1,10 +1,10 @@
 
-thread 'main' panicked at tests/fail/panic/abort_unwind.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/panic/abort_unwind.rs:LL:CC:
 PANIC!!!
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'main' panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
+thread 'main' ($TID) panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
 panic in a function that cannot unwind
 stack backtrace:
 thread caused non-unwinding panic. aborting.
diff --git a/src/tools/miri/tests/fail/panic/bad_unwind.stderr b/src/tools/miri/tests/fail/panic/bad_unwind.stderr
index b8404c4e457..b0a8492b6a6 100644
--- a/src/tools/miri/tests/fail/panic/bad_unwind.stderr
+++ b/src/tools/miri/tests/fail/panic/bad_unwind.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/panic/bad_unwind.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/panic/bad_unwind.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/fail/panic/double_panic.stderr b/src/tools/miri/tests/fail/panic/double_panic.stderr
index 3f1fbfef721..f6aa0a34749 100644
--- a/src/tools/miri/tests/fail/panic/double_panic.stderr
+++ b/src/tools/miri/tests/fail/panic/double_panic.stderr
@@ -1,14 +1,14 @@
 
-thread 'main' panicked at tests/fail/panic/double_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/panic/double_panic.rs:LL:CC:
 first
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'main' panicked at tests/fail/panic/double_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/panic/double_panic.rs:LL:CC:
 second
 stack backtrace:
 
-thread 'main' panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
+thread 'main' ($TID) panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
 panic in a destructor during cleanup
 thread caused non-unwinding panic. aborting.
 error: abnormal termination: the program aborted execution
diff --git a/src/tools/miri/tests/fail/panic/panic_abort1.stderr b/src/tools/miri/tests/fail/panic/panic_abort1.stderr
index 9aca2ed654f..ebdf57f0f03 100644
--- a/src/tools/miri/tests/fail/panic/panic_abort1.stderr
+++ b/src/tools/miri/tests/fail/panic/panic_abort1.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/panic/panic_abort1.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/panic/panic_abort1.rs:LL:CC:
 panicking from libstd
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/fail/panic/panic_abort2.stderr b/src/tools/miri/tests/fail/panic/panic_abort2.stderr
index 425817d5f86..d63e4ed79b2 100644
--- a/src/tools/miri/tests/fail/panic/panic_abort2.stderr
+++ b/src/tools/miri/tests/fail/panic/panic_abort2.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/panic/panic_abort2.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/panic/panic_abort2.rs:LL:CC:
 42-panicking from libstd
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/fail/panic/panic_abort3.stderr b/src/tools/miri/tests/fail/panic/panic_abort3.stderr
index a21e185219e..9751053396a 100644
--- a/src/tools/miri/tests/fail/panic/panic_abort3.stderr
+++ b/src/tools/miri/tests/fail/panic/panic_abort3.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/panic/panic_abort3.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/panic/panic_abort3.rs:LL:CC:
 panicking from libcore
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/fail/panic/panic_abort4.stderr b/src/tools/miri/tests/fail/panic/panic_abort4.stderr
index a3cf5d72198..a84824fcc81 100644
--- a/src/tools/miri/tests/fail/panic/panic_abort4.stderr
+++ b/src/tools/miri/tests/fail/panic/panic_abort4.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/panic/panic_abort4.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/panic/panic_abort4.rs:LL:CC:
 42-panicking from libcore
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/fail/panic/tls_macro_const_drop_panic.stderr b/src/tools/miri/tests/fail/panic/tls_macro_const_drop_panic.stderr
index 1dcdb4a3996..ef87e7fe6db 100644
--- a/src/tools/miri/tests/fail/panic/tls_macro_const_drop_panic.stderr
+++ b/src/tools/miri/tests/fail/panic/tls_macro_const_drop_panic.stderr
@@ -1,5 +1,5 @@
 
-thread $NAME panicked at tests/fail/panic/tls_macro_const_drop_panic.rs:LL:CC:
+thread $NAME ($TID) panicked at tests/fail/panic/tls_macro_const_drop_panic.rs:LL:CC:
 ow
 fatal runtime error: thread local panicked on drop, aborting
 error: abnormal termination: the program aborted execution
diff --git a/src/tools/miri/tests/fail/panic/tls_macro_drop_panic.stderr b/src/tools/miri/tests/fail/panic/tls_macro_drop_panic.stderr
index 7e4907abd93..4fdaa97e1d0 100644
--- a/src/tools/miri/tests/fail/panic/tls_macro_drop_panic.stderr
+++ b/src/tools/miri/tests/fail/panic/tls_macro_drop_panic.stderr
@@ -1,5 +1,5 @@
 
-thread $NAME panicked at tests/fail/panic/tls_macro_drop_panic.rs:LL:CC:
+thread $NAME ($TID) panicked at tests/fail/panic/tls_macro_drop_panic.rs:LL:CC:
 ow
 fatal runtime error: thread local panicked on drop, aborting
 error: abnormal termination: the program aborted execution
diff --git a/src/tools/miri/tests/fail/ptr_swap_nonoverlapping.stderr b/src/tools/miri/tests/fail/ptr_swap_nonoverlapping.stderr
index 8295a581060..d2b557f13f3 100644
--- a/src/tools/miri/tests/fail/ptr_swap_nonoverlapping.stderr
+++ b/src/tools/miri/tests/fail/ptr_swap_nonoverlapping.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/fail/ptr_swap_nonoverlapping.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/ptr_swap_nonoverlapping.rs:LL:CC:
 unsafe precondition(s) violated: ptr::swap_nonoverlapping requires that both pointer arguments are aligned and non-null and the specified memory ranges do not overlap
 
 This indicates a bug in the program. This Undefined Behavior check is optional, and cannot be relied on for safety.
diff --git a/src/tools/miri/tests/fail/terminate-terminator.stderr b/src/tools/miri/tests/fail/terminate-terminator.stderr
index f0f305d76bc..96df302c397 100644
--- a/src/tools/miri/tests/fail/terminate-terminator.stderr
+++ b/src/tools/miri/tests/fail/terminate-terminator.stderr
@@ -1,12 +1,12 @@
 warning: You have explicitly enabled MIR optimizations, overriding Miri's default which is to completely disable them. Any optimizations may hide UB that Miri would otherwise detect, and it is not necessarily possible to predict what kind of UB will be missed. If you are enabling optimizations to make Miri run faster, we advise using cfg(miri) to shrink your workload instead. The performance benefit of enabling MIR optimizations is usually marginal at best.
 
 
-thread 'main' panicked at tests/fail/terminate-terminator.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/terminate-terminator.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'main' panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
+thread 'main' ($TID) panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
 panic in a function that cannot unwind
 stack backtrace:
 thread caused non-unwinding panic. aborting.
diff --git a/src/tools/miri/tests/fail/unwind-action-terminate.stderr b/src/tools/miri/tests/fail/unwind-action-terminate.stderr
index 216ae84512a..06c63c70ede 100644
--- a/src/tools/miri/tests/fail/unwind-action-terminate.stderr
+++ b/src/tools/miri/tests/fail/unwind-action-terminate.stderr
@@ -1,10 +1,10 @@
 
-thread 'main' panicked at tests/fail/unwind-action-terminate.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/fail/unwind-action-terminate.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'main' panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
+thread 'main' ($TID) panicked at RUSTLIB/core/src/panicking.rs:LL:CC:
 panic in a function that cannot unwind
 stack backtrace:
 thread caused non-unwinding panic. aborting.
diff --git a/src/tools/miri/tests/panic/alloc_error_handler_hook.stderr b/src/tools/miri/tests/panic/alloc_error_handler_hook.stderr
index 2be06968321..ad2bfc3f2a3 100644
--- a/src/tools/miri/tests/panic/alloc_error_handler_hook.stderr
+++ b/src/tools/miri/tests/panic/alloc_error_handler_hook.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/alloc_error_handler_hook.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/alloc_error_handler_hook.rs:LL:CC:
 alloc error hook called
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/alloc_error_handler_panic.stderr b/src/tools/miri/tests/panic/alloc_error_handler_panic.stderr
index ddee4fd6ce3..7c2d089f952 100644
--- a/src/tools/miri/tests/panic/alloc_error_handler_panic.stderr
+++ b/src/tools/miri/tests/panic/alloc_error_handler_panic.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at RUSTLIB/std/src/alloc.rs:LL:CC:
+thread 'main' ($TID) panicked at RUSTLIB/std/src/alloc.rs:LL:CC:
 memory allocation of 4 bytes failed
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/div-by-zero-2.stderr b/src/tools/miri/tests/panic/div-by-zero-2.stderr
index 4d4b0062d5e..013f3cd3c20 100644
--- a/src/tools/miri/tests/panic/div-by-zero-2.stderr
+++ b/src/tools/miri/tests/panic/div-by-zero-2.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/div-by-zero-2.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/div-by-zero-2.rs:LL:CC:
 attempt to divide by zero
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/function_calls/exported_symbol_good_unwind.stderr b/src/tools/miri/tests/panic/function_calls/exported_symbol_good_unwind.stderr
index 8bcd635e8be..dad94377d12 100644
--- a/src/tools/miri/tests/panic/function_calls/exported_symbol_good_unwind.stderr
+++ b/src/tools/miri/tests/panic/function_calls/exported_symbol_good_unwind.stderr
@@ -1,11 +1,11 @@
 
-thread 'main' panicked at tests/panic/function_calls/exported_symbol_good_unwind.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/function_calls/exported_symbol_good_unwind.rs:LL:CC:
 explicit panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'main' panicked at tests/panic/function_calls/exported_symbol_good_unwind.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/function_calls/exported_symbol_good_unwind.rs:LL:CC:
 explicit panic
 
-thread 'main' panicked at tests/panic/function_calls/exported_symbol_good_unwind.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/function_calls/exported_symbol_good_unwind.rs:LL:CC:
 explicit panic
diff --git a/src/tools/miri/tests/panic/mir-validation.rs b/src/tools/miri/tests/panic/mir-validation.rs
index e4b75cccbb5..b9097f2e8c5 100644
--- a/src/tools/miri/tests/panic/mir-validation.rs
+++ b/src/tools/miri/tests/panic/mir-validation.rs
@@ -8,6 +8,12 @@
 // Somehow on rustc Windows CI, the "Miri caused an ICE" message is not shown
 // and we don't even get a regular panic; rustc aborts with a different exit code instead.
 //@ignore-host: windows
+
+// FIXME: this tests a crash in rustc. For stage1, rustc is built with the downloaded standard
+// library which doesn't yet print the thread ID. Normalization can be removed at the stage bump.
+// For the grep: cfg(bootstrap)
+//@normalize-stderr-test: "thread 'rustc' panicked" -> "thread 'rustc' ($$TID) panicked"
+
 #![feature(custom_mir, core_intrinsics)]
 use core::intrinsics::mir::*;
 
diff --git a/src/tools/miri/tests/panic/mir-validation.stderr b/src/tools/miri/tests/panic/mir-validation.stderr
index f801ac907e6..1d40c93d709 100644
--- a/src/tools/miri/tests/panic/mir-validation.stderr
+++ b/src/tools/miri/tests/panic/mir-validation.stderr
@@ -6,7 +6,7 @@ LL |             *(tuple.0) = 1;
    |             ^^^^^^^^^^^^^^
 
 
-thread 'rustc' panicked at compiler/rustc_mir_transform/src/validate.rs:LL:CC:
+thread 'rustc' ($TID) panicked at compiler/rustc_mir_transform/src/validate.rs:LL:CC:
 Box<dyn Any>
 stack backtrace:
 
diff --git a/src/tools/miri/tests/panic/oob_subslice.stderr b/src/tools/miri/tests/panic/oob_subslice.stderr
index c0dabaff772..f8270f4ad4d 100644
--- a/src/tools/miri/tests/panic/oob_subslice.stderr
+++ b/src/tools/miri/tests/panic/oob_subslice.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/oob_subslice.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/oob_subslice.rs:LL:CC:
 range end index 5 out of range for slice of length 4
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/overflowing-lsh-neg.stderr b/src/tools/miri/tests/panic/overflowing-lsh-neg.stderr
index d674e2beb8d..8e618b978ef 100644
--- a/src/tools/miri/tests/panic/overflowing-lsh-neg.stderr
+++ b/src/tools/miri/tests/panic/overflowing-lsh-neg.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/overflowing-lsh-neg.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/overflowing-lsh-neg.rs:LL:CC:
 attempt to shift left with overflow
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/overflowing-rsh-1.stderr b/src/tools/miri/tests/panic/overflowing-rsh-1.stderr
index bb94f2e12c4..471bc849abb 100644
--- a/src/tools/miri/tests/panic/overflowing-rsh-1.stderr
+++ b/src/tools/miri/tests/panic/overflowing-rsh-1.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/overflowing-rsh-1.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/overflowing-rsh-1.rs:LL:CC:
 attempt to shift right with overflow
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/overflowing-rsh-2.stderr b/src/tools/miri/tests/panic/overflowing-rsh-2.stderr
index 0a29a57f3e1..94f5fb0f1ca 100644
--- a/src/tools/miri/tests/panic/overflowing-rsh-2.stderr
+++ b/src/tools/miri/tests/panic/overflowing-rsh-2.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/overflowing-rsh-2.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/overflowing-rsh-2.rs:LL:CC:
 attempt to shift right with overflow
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/panic1.stderr b/src/tools/miri/tests/panic/panic1.stderr
index 130bc7737a4..9ca5234dd03 100644
--- a/src/tools/miri/tests/panic/panic1.stderr
+++ b/src/tools/miri/tests/panic/panic1.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/panic1.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/panic1.rs:LL:CC:
 panicking from libstd
 stack backtrace:
    0: std::panicking::begin_panic_handler
diff --git a/src/tools/miri/tests/panic/panic2.stderr b/src/tools/miri/tests/panic/panic2.stderr
index 157ffdb6b5d..c2e55178333 100644
--- a/src/tools/miri/tests/panic/panic2.stderr
+++ b/src/tools/miri/tests/panic/panic2.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/panic2.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/panic2.rs:LL:CC:
 42-panicking from libstd
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/panic3.stderr b/src/tools/miri/tests/panic/panic3.stderr
index 529ef70870b..2fc761a4f3d 100644
--- a/src/tools/miri/tests/panic/panic3.stderr
+++ b/src/tools/miri/tests/panic/panic3.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/panic3.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/panic3.rs:LL:CC:
 panicking from libcore
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/panic4.stderr b/src/tools/miri/tests/panic/panic4.stderr
index ecd07dd7ded..f2f4c038000 100644
--- a/src/tools/miri/tests/panic/panic4.stderr
+++ b/src/tools/miri/tests/panic/panic4.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/panic4.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/panic4.rs:LL:CC:
 42-panicking from libcore
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/panic/transmute_fat2.stderr b/src/tools/miri/tests/panic/transmute_fat2.stderr
index 71e2d7a8208..8846c4c7fbc 100644
--- a/src/tools/miri/tests/panic/transmute_fat2.stderr
+++ b/src/tools/miri/tests/panic/transmute_fat2.stderr
@@ -1,5 +1,5 @@
 
-thread 'main' panicked at tests/panic/transmute_fat2.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/panic/transmute_fat2.rs:LL:CC:
 index out of bounds: the len is 0 but the index is 0
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
diff --git a/src/tools/miri/tests/pass/panic/catch_panic.stderr b/src/tools/miri/tests/pass/panic/catch_panic.stderr
index bc745fca578..cd7384fb107 100644
--- a/src/tools/miri/tests/pass/panic/catch_panic.stderr
+++ b/src/tools/miri/tests/pass/panic/catch_panic.stderr
@@ -1,47 +1,47 @@
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 Hello from std::panic
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 Caught panic message (&str): Hello from std::panic
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 Hello from std::panic: 1
 Caught panic message (String): Hello from std::panic: 1
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 Hello from std::panic_any: 2
 Caught panic message (String): Hello from std::panic_any: 2
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 Box<dyn Any>
 Failed to get caught panic message.
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 Hello from core::panic
 Caught panic message (&str): Hello from core::panic
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 Hello from core::panic: 5
 Caught panic message (String): Hello from core::panic: 5
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 index out of bounds: the len is 3 but the index is 4
 Caught panic message (String): index out of bounds: the len is 3 but the index is 4
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 attempt to divide by zero
 Caught panic message (&str): attempt to divide by zero
 
-thread 'main' panicked at RUSTLIB/core/src/ptr/const_ptr.rs:LL:CC:
+thread 'main' ($TID) panicked at RUSTLIB/core/src/ptr/const_ptr.rs:LL:CC:
 align_offset: align is not a power-of-two
 Caught panic message (&str): align_offset: align is not a power-of-two
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 assertion failed: false
 Caught panic message (&str): assertion failed: false
 
-thread 'main' panicked at tests/pass/panic/catch_panic.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/catch_panic.rs:LL:CC:
 assertion failed: false
 Caught panic message (&str): assertion failed: false
 Success!
diff --git a/src/tools/miri/tests/pass/panic/concurrent-panic.stderr b/src/tools/miri/tests/pass/panic/concurrent-panic.stderr
index 4a3ac16debc..b388a3bedc0 100644
--- a/src/tools/miri/tests/pass/panic/concurrent-panic.stderr
+++ b/src/tools/miri/tests/pass/panic/concurrent-panic.stderr
@@ -1,7 +1,7 @@
 Thread 1 starting, will block on mutex
 Thread 1 reported it has started
 
-thread '<unnamed>' panicked at tests/pass/panic/concurrent-panic.rs:LL:CC:
+thread '<unnamed>' ($TID) panicked at tests/pass/panic/concurrent-panic.rs:LL:CC:
 panic in thread 2
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
@@ -9,7 +9,7 @@ Thread 2 blocking on thread 1
 Thread 2 reported it has started
 Unlocking mutex
 
-thread '<unnamed>' panicked at tests/pass/panic/concurrent-panic.rs:LL:CC:
+thread '<unnamed>' ($TID) panicked at tests/pass/panic/concurrent-panic.rs:LL:CC:
 panic in thread 1
 Thread 1 has exited
 Thread 2 has exited
diff --git a/src/tools/miri/tests/pass/panic/nested_panic_caught.stderr b/src/tools/miri/tests/pass/panic/nested_panic_caught.stderr
index 8aff8f6ec55..7ae39204d4e 100644
--- a/src/tools/miri/tests/pass/panic/nested_panic_caught.stderr
+++ b/src/tools/miri/tests/pass/panic/nested_panic_caught.stderr
@@ -1,9 +1,9 @@
 
-thread 'main' panicked at tests/pass/panic/nested_panic_caught.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/nested_panic_caught.rs:LL:CC:
 once
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'main' panicked at tests/pass/panic/nested_panic_caught.rs:LL:CC:
+thread 'main' ($TID) panicked at tests/pass/panic/nested_panic_caught.rs:LL:CC:
 twice
 stack backtrace:
diff --git a/src/tools/miri/tests/pass/panic/thread_panic.stderr b/src/tools/miri/tests/pass/panic/thread_panic.stderr
index 3bb2991805c..92403d5152d 100644
--- a/src/tools/miri/tests/pass/panic/thread_panic.stderr
+++ b/src/tools/miri/tests/pass/panic/thread_panic.stderr
@@ -1,8 +1,8 @@
 
-thread '<unnamed>' panicked at tests/pass/panic/thread_panic.rs:LL:CC:
+thread '<unnamed>' ($TID) panicked at tests/pass/panic/thread_panic.rs:LL:CC:
 Hello!
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 note: in Miri, you may have to set `MIRIFLAGS=-Zmiri-env-forward=RUST_BACKTRACE` for the environment variable to have an effect
 
-thread 'childthread' panicked at tests/pass/panic/thread_panic.rs:LL:CC:
+thread 'childthread' ($TID) panicked at tests/pass/panic/thread_panic.rs:LL:CC:
 Hello, world!
diff --git a/src/tools/rustfmt/tests/rustfmt/main.rs b/src/tools/rustfmt/tests/rustfmt/main.rs
index a9f58b9328e..4a9399377d1 100644
--- a/src/tools/rustfmt/tests/rustfmt/main.rs
+++ b/src/tools/rustfmt/tests/rustfmt/main.rs
@@ -185,10 +185,11 @@ fn dont_emit_ICE() {
         "tests/target/issue-6105.rs",
     ];
 
+    let panic_re = regex::Regex::new("thread.*panicked").unwrap();
     for file in files {
         let args = [file];
         let (_stdout, stderr) = rustfmt(&args);
-        assert!(!stderr.contains("thread 'main' panicked"));
+        assert!(!panic_re.is_match(&stderr));
     }
 }