From bd7b8b3612f8b62d215cac218f752a28eada7d7e Mon Sep 17 00:00:00 2001 From: Jieyou Xu Date: Fri, 1 Aug 2025 21:29:05 +0800 Subject: [PATCH] Properly pass path to staged `rustc` to `compiletest` self-tests Otherwise, this can do weird things like use a global rustc, or try to use stage 0 rustc. This must be properly configured, because `compiletest` is intended to only support one compiler target spec JSON format (of the in-tree compiler). --- src/bootstrap/src/core/build_steps/test.rs | 6 ++++++ src/tools/compiletest/src/directives/tests.rs | 18 ++---------------- 2 files changed, 8 insertions(+), 16 deletions(-) diff --git a/src/bootstrap/src/core/build_steps/test.rs b/src/bootstrap/src/core/build_steps/test.rs index 951ca73fcc494..3eadd325b8115 100644 --- a/src/bootstrap/src/core/build_steps/test.rs +++ b/src/bootstrap/src/core/build_steps/test.rs @@ -749,6 +749,12 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the SourceType::InTree, &[], ); + + // Used for `compiletest` self-tests to have the path to the *staged* compiler. Getting this + // right is important, as `compiletest` is intended to only support one target spec JSON + // format, namely that of the staged compiler. + cargo.env("TEST_RUSTC", builder.rustc(compiler)); + cargo.allow_features(COMPILETEST_ALLOW_FEATURES); run_cargo_test(cargo, &[], &[], "compiletest self test", host, builder); } diff --git a/src/tools/compiletest/src/directives/tests.rs b/src/tools/compiletest/src/directives/tests.rs index 5682cc57b6f6e..30d8537b51a56 100644 --- a/src/tools/compiletest/src/directives/tests.rs +++ b/src/tools/compiletest/src/directives/tests.rs @@ -203,22 +203,8 @@ impl ConfigBuilder { } args.push("--rustc-path".to_string()); - // This is a subtle/fragile thing. On rust-lang CI, there is no global - // `rustc`, and Cargo doesn't offer a convenient way to get the path to - // `rustc`. Fortunately bootstrap sets `RUSTC` for us, which is pointing - // to the stage0 compiler. - // - // Otherwise, if you are running compiletests's tests manually, you - // probably don't have `RUSTC` set, in which case this falls back to the - // global rustc. If your global rustc is too far out of sync with stage0, - // then this may cause confusing errors. Or if for some reason you don't - // have rustc in PATH, that would also fail. - args.push(std::env::var("RUSTC").unwrap_or_else(|_| { - eprintln!( - "warning: RUSTC not set, using global rustc (are you not running via bootstrap?)" - ); - "rustc".to_string() - })); + args.push(std::env::var("TEST_RUSTC").expect("must be configured by bootstrap")); + crate::parse_config(args) } }