From ad480883731716b38a5aaed8eaa37bcc6bb6454c Mon Sep 17 00:00:00 2001
From: hi-rustin <rustin.liu@gmail.com>
Date: Sat, 8 Jul 2023 11:49:04 +0800
Subject: [PATCH] Add comment for `cargo::` syntax

Signed-off-by: hi-rustin <rustin.liu@gmail.com>
---
 src/cargo/core/compiler/custom_build.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/cargo/core/compiler/custom_build.rs b/src/cargo/core/compiler/custom_build.rs
index ebc68f0030ea..38c27df5777d 100644
--- a/src/cargo/core/compiler/custom_build.rs
+++ b/src/cargo/core/compiler/custom_build.rs
@@ -691,6 +691,9 @@ impl BuildOutput {
             }
             let data = match iter.next() {
                 Some(val) => {
+                    // `cargo::` is reserved for future use or some way to indicate that there is a version mismatch
+                    // between the build script and cargo, whether its because no MSRV was specified
+                    // or someone was reading too new of documentation.
                     if val.starts_with(":") {
                         // Line started with `cargo::`.
                         bail!("invalid output in {}: `{}`\n\