fix: emit 1.77 syntax error only when msrv is incompatible

src/cargo/core/compiler/custom_build.rs

@@ -724,10 +724,9 @@ impl BuildOutput {
             pkg_descr: &str,
             msrv: &Option<RustVersion>,
         ) -> CargoResult<()> {
-            let new_syntax_added_in = &RustVersion::from_str("1.77.0")?;
-
             if let Some(msrv) = msrv {
-                if msrv < new_syntax_added_in {
+                let new_syntax_added_in = RustVersion::from_str("1.77.0")?;
+                if !new_syntax_added_in.is_compatible_with(msrv.as_partial()) {
                     bail!(
                         "the `cargo::` syntax for build script output instructions was added in \
                         Rust 1.77.0, but the minimum supported Rust version of `{pkg_descr}` is {msrv}.\n\

tests/testsuite/build_script.rs

@@ -5527,14 +5527,9 @@ fn test_new_syntax_with_compatible_partial_msrv() {
         .build();
 
     p.cargo("check")
-        .with_status(101)
         .with_stderr_contains(
             "\
 [COMPILING] foo [..]
-[ERROR] the `cargo::` syntax for build script output instructions was added in Rust 1.77.0, \
-but the minimum supported Rust version of `foo v0.0.0 ([ROOT]/foo)` is 1.77.
-See https://doc.rust-lang.org/cargo/reference/build-scripts.html#outputs-of-the-build-script \
-for more information about build script outputs.
 ",
         )
         .run();