miri tests can always rely on CARGO_BIN_EXE_miri

Author: RalfJung

src/bootstrap/src/core/build_steps/test.rs

@@ -679,7 +679,6 @@ impl Step for Miri {
         // miri tests need to know about the stage sysroot
         cargo.env("MIRI_SYSROOT", &miri_sysroot);
         cargo.env("MIRI_HOST_SYSROOT", &host_sysroot);
-        cargo.env("MIRI", &miri.tool_path);
 
         // Set the target.
         cargo.env("MIRI_TEST_TARGET", target.rustc_target_arg());

src/tools/miri/tests/ui.rs

@@ -27,7 +27,7 @@ enum Mode {
 }
 
 fn miri_path() -> PathBuf {
-    PathBuf::from(env::var("MIRI").unwrap_or_else(|_| env!("CARGO_BIN_EXE_miri").into()))
+    env!("CARGO_BIN_EXE_miri").into()
 }
 
 // Build the shared object file for testing native function calls.