bootstrap: Move `-Zdual-proc-macros` to `builder.rs`

1 files changed, 0 insertions, 6 deletions

diff --git a/src/bootstrap/bin/rustc.rs b/src/bootstrap/bin/rustc.rs
index 3c836ce261d..1955ca4aa99 100644
--- a/src/bootstrap/bin/rustc.rs
+++ b/src/bootstrap/bin/rustc.rs
@@ -124,12 +124,6 @@ fn main() {
             cmd.arg("--sysroot").arg(&sysroot);
         }
 
-        // Link crates to the proc macro crate for the target, but use a host proc macro crate
-        // to actually run the macros
-        if env::var_os("RUST_DUAL_PROC_MACROS").is_some() {
-            cmd.arg("-Zdual-proc-macros");
-        }
-
         // When we build Rust dylibs they're all intended for intermediate
         // usage, so make sure we pass the -Cprefer-dynamic flag instead of
         // linking all deps statically into the dylib.