Remove CARGO_VERSION* env vars

Cargo and Rustc are co-versioned at the moment anyway.

Author: Jon Gjengset

src/cargo/core/compiler/custom_build.rs

@@ -256,14 +256,6 @@ fn build_work(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Job> {
         cmd.env_remove("RUSTC_WRAPPER");
     }
     cmd.env("RUSTFLAGS", bcx.rustflags_args(unit).join(" "));
-    let version = crate::version();
-    cmd.env(
-        "CARGO_VERSION",
-        format!("{}.{}.{}", version.major, version.minor, version.patch),
-    );
-    cmd.env("CARGO_VERSION_MAJOR", version.major.to_string());
-    cmd.env("CARGO_VERSION_MINOR", version.minor.to_string());
-    cmd.env("CARGO_VERSION_PATCH", version.patch.to_string());
     let version = &bcx.rustc().version;
     cmd.env(
         "RUSTC_VERSION",

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

@@ -344,9 +344,6 @@ let out_dir = env::var("OUT_DIR").unwrap();
 * `RUSTFLAGS` — the `RUSTFLAGS` that Cargo invokes `rustc` with.
                 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].
-* `CARGO_VERSION` - The version of cargo used to invoke the build
-                    script. Its constituent parts are also available as
-		    `CARGO_VERSION_MAJOR`, `_MINOR`, and `_PATCH`.
 * `RUSTC_VERSION` - The version of rustc used by the cargo that invokes
 		    the build script. Its constituent parts are also
 		    available as `CARGO_VERSION_MAJOR`, `_MINOR`, and

tests/testsuite/build_script.rs

@@ -82,7 +82,6 @@ fn custom_build_env_vars() {
         )
         .file("bar/src/lib.rs", "pub fn hello() {}");
 
-    let cargo_version = cargo::version();
     let rustc_version = semver::Version::parse(rustc_release()).unwrap();
     let file_content = format!(
         r#"
@@ -126,33 +125,21 @@ fn custom_build_env_vars() {
                 let rustflags = env::var("RUSTFLAGS").unwrap();
                 assert_eq!(rustflags, "");
 
-                let version = env::var("CARGO_VERSION").unwrap();
-                assert_eq!(version, "{1}.{2}.{3}", "bad cargo version");
-                let version = env::var("CARGO_VERSION_MAJOR").unwrap();
-                assert_eq!(version, "{1}");
-                let version = env::var("CARGO_VERSION_MINOR").unwrap();
-                assert_eq!(version, "{2}");
-                let version = env::var("CARGO_VERSION_PATCH").unwrap();
-                assert_eq!(version, "{3}");
-
                 let version = env::var("RUSTC_VERSION").unwrap();
-                assert_eq!(version, "{4}.{5}.{6}", "bad rust version");
+                assert_eq!(version, "{1}.{2}.{3}", "bad rust version");
                 let version = env::var("RUSTC_VERSION_MAJOR").unwrap();
-                assert_eq!(version, "{4}");
+                assert_eq!(version, "{1}");
                 let version = env::var("RUSTC_VERSION_MINOR").unwrap();
-                assert_eq!(version, "{5}");
+                assert_eq!(version, "{2}");
                 let version = env::var("RUSTC_VERSION_PATCH").unwrap();
-                assert_eq!(version, "{6}");
+                assert_eq!(version, "{3}");
             }}
         "#,
         p.root()
             .join("target")
             .join("debug")
             .join("build")
             .display(),
-        cargo_version.major,
-        cargo_version.minor,
-        cargo_version.patch,
         rustc_version.major,
         rustc_version.minor,
         rustc_version.patch,