Allow `traps.rs` tests to pass even when `RUST_BACKTRACE=1` on nightly Rust (#7950)

* Allow `traps.rs` tests to pass even when `RUST_BACKTRACE=1` on nightly Rust

Instead of asserting exact error messages, which `anyhow` auto adds Rust
backtrace to on nightly, assert that the important bits are there.

* Use `contains` on the whole error message when possible

tests/all/traps.rs

@@ -307,8 +307,8 @@ fn trap_display_pretty() -> Result<()> {
     let run_func = instance.get_typed_func::<(), ()>(&mut store, "bar")?;
 
     let e = run_func.call(&mut store, ()).unwrap_err();
-    assert_eq!(
-        format!("{:?}", e),
+    let e = format!("{e:?}");
+    assert!(e.contains(
         "\
 error while executing at wasm backtrace:
     0:   0x23 - m!die
@@ -319,7 +319,7 @@ error while executing at wasm backtrace:
 Caused by:
     wasm trap: wasm `unreachable` instruction executed\
 "
-    );
+    ));
     Ok(())
 }
 
@@ -351,8 +351,8 @@ fn trap_display_multi_module() -> Result<()> {
     let bar2 = instance.get_typed_func::<(), ()>(&mut store, "bar2")?;
 
     let e = bar2.call(&mut store, ()).unwrap_err();
-    assert_eq!(
-        format!("{e:?}"),
+    let e = format!("{e:?}");
+    assert!(e.contains(
         "\
 error while executing at wasm backtrace:
     0:   0x23 - a!die
@@ -365,7 +365,7 @@ error while executing at wasm backtrace:
 Caused by:
     wasm trap: wasm `unreachable` instruction executed\
 "
-    );
+    ));
     Ok(())
 }
 
@@ -592,11 +592,10 @@ fn start_trap_pretty() -> Result<()> {
     let module = Module::new(store.engine(), wat)?;
     let e = match Instance::new(&mut store, &module, &[]) {
         Ok(_) => panic!("expected failure"),
-        Err(e) => e,
+        Err(e) => format!("{e:?}"),
     };
 
-    assert_eq!(
-        format!("{e:?}"),
+    assert!(e.contains(
         "\
 error while executing at wasm backtrace:
     0:   0x1d - m!die
@@ -607,7 +606,7 @@ error while executing at wasm backtrace:
 Caused by:
     wasm trap: wasm `unreachable` instruction executed\
 "
-    );
+    ));
     Ok(())
 }
 
@@ -800,8 +799,8 @@ fn no_hint_even_with_dwarf_info() -> Result<()> {
         "#,
     )?;
     let trap = Instance::new(&mut store, &module, &[]).unwrap_err();
-    assert_eq!(
-        format!("{trap:?}"),
+    let trap = format!("{trap:?}");
+    assert!(trap.contains(
         "\
 error while executing at wasm backtrace:
     0:   0x1a - <unknown>!start
@@ -809,7 +808,8 @@ error while executing at wasm backtrace:
 Caused by:
     wasm trap: wasm `unreachable` instruction executed\
 "
-    );
+    ));
+    assert!(!trap.contains("WASM_BACKTRACE_DETAILS"));
     Ok(())
 }
 
@@ -833,17 +833,16 @@ fn hint_with_dwarf_info() -> Result<()> {
         "#,
     )?;
     let trap = Instance::new(&mut store, &module, &[]).unwrap_err();
-    assert_eq!(
-        format!("{trap:?}"),
+    let trap = format!("{trap:?}");
+    assert!(trap.contains(
         "\
 error while executing at wasm backtrace:
     0:   0x1a - <unknown>!start
 note: using the `WASMTIME_BACKTRACE_DETAILS=1` environment variable may show more debugging information
 
 Caused by:
-    wasm trap: wasm `unreachable` instruction executed\
-"
-    );
+    wasm trap: wasm `unreachable` instruction executed"
+    ));
     Ok(())
 }