Remove RUSTC_VERSION envvar

crates/cargo-test-support/src/lib.rs

@@ -1041,14 +1041,6 @@ pub fn is_nightly() -> bool {
         && (vv.contains("-nightly") || vv.contains("-dev"))
 }
 
-pub fn rustc_release() -> &'static str {
-    RUSTC_INFO
-        .verbose_version
-        .lines()
-        .find_map(|line| line.strip_prefix("release: "))
-        .expect("verbose version has release: field")
-}
-
 pub fn process<T: AsRef<OsStr>>(t: T) -> ProcessBuilder {
     _process(t.as_ref())
 }

src/cargo/core/compiler/custom_build.rs

@@ -266,14 +266,6 @@ fn build_work(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Job> {
         bcx.rustflags_args(unit).join("\x1f"),
     );
     cmd.env_remove("RUSTFLAGS");
-    let version = &bcx.rustc().version;
-    cmd.env(
-        "RUSTC_VERSION",
-        format!("{}.{}.{}", version.major, version.minor, version.patch),
-    );
-    cmd.env("RUSTC_VERSION_MAJOR", version.major.to_string());
-    cmd.env("RUSTC_VERSION_MINOR", version.minor.to_string());
-    cmd.env("RUSTC_VERSION_PATCH", version.patch.to_string());
 
     // Gather the set of native dependencies that this package has along with
     // some other variables to close over.

src/doc/src/reference/environment-variables.md

@@ -355,10 +355,6 @@ let out_dir = env::var("OUT_DIR").unwrap();
 			      (ASCII Unit Separator). See
 			      [`build.rustflags`].
 * `CARGO_PKG_<var>` - The package information variables, with the same names and values as are [provided during crate building][variables set for crates].
-* `RUSTC_VERSION` - The version of rustc used by the cargo that invokes
-		    the build script. Its constituent parts are also
-		    available as `RUSTC_VERSION_MAJOR`, `_MINOR`, and
-		    `_PATCH`.
 
 [unix-like platforms]: ../../reference/conditional-compilation.html#unix-and-windows
 [windows-like platforms]: ../../reference/conditional-compilation.html#unix-and-windows

tests/testsuite/build_script.rs

@@ -5,9 +5,7 @@ use cargo_test_support::paths::CargoPathExt;
 use cargo_test_support::registry::Package;
 use cargo_test_support::tools;
 use cargo_test_support::{basic_manifest, cross_compile, is_coarse_mtime, project};
-use cargo_test_support::{
-    rustc_host, rustc_release, sleep_ms, slow_cpu_multiplier, symlink_supported,
-};
+use cargo_test_support::{rustc_host, sleep_ms, slow_cpu_multiplier, symlink_supported};
 use cargo_util::paths::remove_dir_all;
 use std::env;
 use std::fs;
@@ -82,7 +80,6 @@ fn custom_build_env_vars() {
         )
         .file("bar/src/lib.rs", "pub fn hello() {}");
 
-    let rustc_version = semver::Version::parse(rustc_release()).unwrap();
     let file_content = format!(
         r#"
             use std::env;
@@ -126,25 +123,13 @@ fn custom_build_env_vars() {
                 assert!(env::var("RUSTFLAGS").is_err());
                 let rustflags = env::var("CARGO_ENCODED_RUSTFLAGS").unwrap();
                 assert_eq!(rustflags, "");
-
-                let version = env::var("RUSTC_VERSION").unwrap();
-                assert_eq!(version, "{1}.{2}.{3}", "bad rust version");
-                let version = env::var("RUSTC_VERSION_MAJOR").unwrap();
-                assert_eq!(version, "{1}");
-                let version = env::var("RUSTC_VERSION_MINOR").unwrap();
-                assert_eq!(version, "{2}");
-                let version = env::var("RUSTC_VERSION_PATCH").unwrap();
-                assert_eq!(version, "{3}");
             }}
         "#,
         p.root()
             .join("target")
             .join("debug")
             .join("build")
             .display(),
-        rustc_version.major,
-        rustc_version.minor,
-        rustc_version.patch,
     );
 
     let p = p.file("bar/build.rs", &file_content).build();