add comments as to the purpose of the different build envvars

[skip ci]
dathere · Aug 9, 2023 · 563119f · 563119f
1 parent 61f227b
commit 563119f
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/build.rs b/build.rs
@@ -1,8 +1,11 @@
 fn main() {
+    // we use TARGET in --version and user-agent strings
     println!(
         "cargo:rustc-env=TARGET={}",
         std::env::var("TARGET").unwrap()
     );
+    // QSV_KIND is used to determine how qsv was built and is displayed in --version
+    // check PERFORMANCE.md for more info
     println!(
         "cargo:rustc-env=QSV_KIND={}",
         std::env::var("QSV_KIND").unwrap_or_else(|_| "compiled".to_string())