Stop setting duplicative CARGO_PKG env vars

Author: dzbarsky

cargo/private/cargo_build_script.bzl

@@ -391,7 +391,6 @@ def _cargo_build_script_impl(ctx):
     env.update({
         "CARGO_CRATE_NAME": name_to_crate_name(pkg_name),
         "CARGO_MANIFEST_DIR": manifest_dir,
-        "CARGO_PKG_NAME": pkg_name,
         "HOST": toolchain.exec_triple.str,
         "NUM_JOBS": "1",
         "OPT_LEVEL": compilation_mode_opt_level,
@@ -406,15 +405,6 @@ def _cargo_build_script_impl(ctx):
         "PROFILE": {"dbg": "debug", "fastbuild": "debug", "opt": "release"}.get(ctx.var["COMPILATION_MODE"], "unknown"),
     })
 
-    if ctx.attr.version:
-        version = ctx.attr.version.split("+")[0].split(".")
-        patch = version[2].split("-") if len(version) > 2 else [""]
-        env["CARGO_PKG_VERSION_MAJOR"] = version[0]
-        env["CARGO_PKG_VERSION_MINOR"] = version[1] if len(version) > 1 else ""
-        env["CARGO_PKG_VERSION_PATCH"] = patch[0]
-        env["CARGO_PKG_VERSION_PRE"] = patch[1] if len(patch) > 1 else ""
-        env["CARGO_PKG_VERSION"] = ctx.attr.version
-
     # Pull in env vars which may be required for the cc_toolchain to work (e.g. on OSX, the SDK version).
     # We hope that the linker env is sufficient for the whole cc_toolchain.
     cc_toolchain, feature_configuration = find_cc_toolchain(ctx)

cargo/private/cargo_build_script_wrapper.bzl

@@ -145,8 +145,6 @@ def cargo_build_script(
         pkg_name = name_to_pkg_name(name)
 
     rustc_env = dict(rustc_env)
-    if "CARGO_PKG_NAME" not in rustc_env:
-        rustc_env["CARGO_PKG_NAME"] = pkg_name
     if "CARGO_CRATE_NAME" not in rustc_env:
         rustc_env["CARGO_CRATE_NAME"] = name_to_crate_name(name_to_pkg_name(name))
 

crate_universe/BUILD.bazel

@@ -1,7 +1,12 @@
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 load("@cui//:defs.bzl", "aliases", "all_crate_deps")
 load("@rules_rust//rust:defs.bzl", "rust_binary", "rust_doc", "rust_doc_test", "rust_library", "rust_test")
-load("//crate_universe:version.bzl", "VERSION")
+load("//cargo:defs.bzl", "cargo_toml_env_vars")
+
+cargo_toml_env_vars(
+    name = "cargo_toml_env_vars",
+    src = "Cargo.toml",
+)
 
 exports_files(
     glob([
@@ -72,7 +77,7 @@ rust_library(
     # for more information). Set stamp = -1 to indicate that it should respect
     # the value of the --stamp commandline flag.
     stamp = -1,
-    version = VERSION,
+    rustc_env_files = [":cargo_toml_env_vars"],
     visibility = ["//visibility:public"],
     deps = all_crate_deps(normal = True),
 )
@@ -81,7 +86,6 @@ rust_binary(
     name = "cargo_bazel_bin",
     srcs = ["src/main.rs"],
     edition = "2021",
-    version = VERSION,
     visibility = ["//visibility:public"],
     deps = [":cargo_bazel"],
 )
@@ -156,6 +160,8 @@ rust_test(
     ),
 )
 
+# TODO(zbarsky): At this point version.bzl only exists to trigger `cargo_bazel_release` GH workflow.
+# Consider swapping that to the main repo's `version.bzl` and remove this.
 rust_test(
     name = "versions_test",
     srcs = ["tests/version_test.rs"],

rust/private/rustc.bzl

@@ -140,26 +140,10 @@ def _get_rustc_env(attr, toolchain, crate_name):
     Returns:
         dict: Rustc environment variables
     """
-    version = attr.version if hasattr(attr, "version") else "0.0.0"
-    major, minor, patch = version.split(".", 2)
-    if "-" in patch:
-        patch, pre = patch.split("-", 1)
-    else:
-        pre = ""
-
     result = {
         "CARGO_CFG_TARGET_ARCH": "" if toolchain.target_arch == None else toolchain.target_arch,
         "CARGO_CFG_TARGET_OS": "" if toolchain.target_os == None else toolchain.target_os,
         "CARGO_CRATE_NAME": crate_name,
-        "CARGO_PKG_AUTHORS": "",
-        "CARGO_PKG_DESCRIPTION": "",
-        "CARGO_PKG_HOMEPAGE": "",
-        "CARGO_PKG_NAME": attr.name,
-        "CARGO_PKG_VERSION": version,
-        "CARGO_PKG_VERSION_MAJOR": major,
-        "CARGO_PKG_VERSION_MINOR": minor,
-        "CARGO_PKG_VERSION_PATCH": patch,
-        "CARGO_PKG_VERSION_PRE": pre,
     }
     if hasattr(attr, "_is_proc_macro_dep_enabled") and attr._is_proc_macro_dep_enabled[IsProcMacroDepEnabledInfo].enabled:
         is_proc_macro_dep = "0"

test/build_env/src/build.rs

@@ -1,8 +1,4 @@
 fn main() {
-    println!(
-        "cargo:rustc-env=CARGO_PKG_NAME_FROM_BUILD_SCRIPT={}",
-        env!("CARGO_PKG_NAME")
-    );
     println!(
         "cargo:rustc-env=CARGO_CRATE_NAME_FROM_BUILD_SCRIPT={}",
         env!("CARGO_CRATE_NAME")

test/build_env/tests/cargo.rs

@@ -1,11 +1,6 @@
 #[test]
 fn cargo_env_vars() {
-    assert_eq!(env!("CARGO_PKG_NAME"), "cargo_env-vars_test");
     assert_eq!(env!("CARGO_CRATE_NAME"), "cargo_env_vars_test");
-    assert_eq!(
-        env!("CARGO_PKG_NAME_FROM_BUILD_SCRIPT"),
-        "cargo_build_script_env-vars"
-    );
     assert_eq!(
         env!("CARGO_CRATE_NAME_FROM_BUILD_SCRIPT"),
         "cargo_build_script_env_vars"

test/build_env/tests/custom_crate_name.rs

@@ -1,8 +1,4 @@
 #[test]
 fn cargo_env_vars() {
-    assert_eq!(
-        env!("CARGO_PKG_NAME"),
-        "cargo-env-vars-custom-crate-name-test"
-    );
     assert_eq!(env!("CARGO_CRATE_NAME"), "custom_crate_name");
 }