feat(build-dir): Added the Cargo version to the inputs of workspace-path-hash

Author: ranger-ross

src/cargo/util/context/mod.rs

@@ -676,7 +676,16 @@ impl GlobalContext {
                         .to_string(),
                 ),
                 ("{workspace-path-hash}", {
-                    let hash = crate::util::hex::short_hash(&workspace_manifest_path);
+                    // We include the version in the hash to prevent external tools from relying on
+                    // our hash implmentation. Note that we explictly do not include the prerelease
+                    // and build parts of the semver to avoid a new hash for every nightly version.
+                    let version = crate::version::version().semver();
+                    let hash = crate::util::hex::short_hash(&(
+                        version.major,
+                        version.minor,
+                        version.patch,
+                        workspace_manifest_path,
+                    ));
                     format!("{}{}{}", &hash[0..2], std::path::MAIN_SEPARATOR, &hash[2..])
                 }),
             ];

src/cargo/version.rs

@@ -35,6 +35,13 @@ pub struct VersionInfo {
     pub description: Option<String>,
 }
 
+impl VersionInfo {
+    /// The Cargo version as a [`semver::Version`].
+    pub fn semver(&self) -> semver::Version {
+        semver::Version::parse(&self.version).expect("Cargo version was not a valid semver version")
+    }
+}
+
 impl fmt::Display for VersionInfo {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{}", self.version)?;
@@ -58,9 +65,7 @@ pub fn version() -> VersionInfo {
         };
     }
 
-    // __CARGO_TEST_CARGO_VERSION is for testing purposes only.
-    let version = std::env::var("__CARGO_TEST_CARGO_VERSION")
-        .ok()
+    let version = version_for_testing()
         // This is the version set in bootstrap, which we use to match rustc.
         .or_else(|| option_env_str!("CFG_RELEASE"))
         .unwrap_or_else(|| {
@@ -100,3 +105,11 @@ pub fn version() -> VersionInfo {
         description,
     }
 }
+
+/// Provides a way for tests to inject an abitrary version for testing purposes.
+///
+// __CARGO_TEST_CARGO_VERSION should not be relied on outside of tests.
+#[allow(clippy::disallowed_methods)]
+fn version_for_testing() -> Option<String> {
+    std::env::var("__CARGO_TEST_CARGO_VERSION").ok()
+}

tests/testsuite/build_dir.rs

@@ -610,7 +610,7 @@ fn template_workspace_path_hash() {
 }
 
 #[cargo_test]
-fn template_workspace_path_hash_should_not_change_between_cargo_versions() {
+fn template_workspace_path_hash_should_change_between_cargo_versions() {
     let p = project()
         .file("src/main.rs", r#"fn main() { println!("Hello, World!") }"#)
         .file(
@@ -661,10 +661,10 @@ fn template_workspace_path_hash_should_not_change_between_cargo_versions() {
     let second_run_build_dir = hash_dir.as_path().join("build-dir");
     assert_build_dir_layout(second_run_build_dir.clone(), "debug");
 
-    // Finally check that the build-dir is in the same location between both Cargo versions
-    assert_eq!(
+    // Finally check that the build-dir is in different location between both Cargo versions
+    assert_ne!(
         first_run_build_dir, second_run_build_dir,
-        "The workspace path hash generated between 2 Cargo versions did not match"
+        "The workspace path hash generated between 2 Cargo versions matched when it should not"
     );
 }