A diff for https://github.com/rust-lang/rust/commit/4c225c4d1732537aff63dd97c2b7ac681fd3d188 that causes https://github.com/Ryan1729/tiny-live-code-example/commit/102b258d641bbbc8cd8eabe13a8cdf4395aaea2e to return a non-zero error code

break.diff

diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index bafe23e..c01717a 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -230,11 +230,6 @@
 // Tell the compiler to link to either panic_abort or panic_unwind
 #![needs_panic_runtime]
 
-// Always use alloc_system during stage0 since we don't know if the alloc_*
-// crate the stage0 compiler will pick by default is available (most
-// obviously, if the user has disabled jemalloc in `./configure`).
-#![cfg_attr(any(stage0, feature = "force_alloc_system"), feature(alloc_system))]
-
 // Turn warnings into errors, but only after stage0, where it can be useful for
 // code to emit warnings during language transitions
 #![deny(warnings)]
@@ -246,6 +241,7 @@
 // compiler details that will never be stable
 #![feature(alloc)]
 #![feature(allocator_api)]
+#![feature(alloc_system)]
 #![feature(allow_internal_unstable)]
 #![feature(asm)]
 #![feature(associated_consts)]
@@ -342,15 +338,13 @@ extern crate core as __core;
 #[macro_use]
 #[macro_reexport(vec, format)]
 extern crate alloc;
+extern crate alloc_system;
 extern crate std_unicode;
 extern crate libc;
 
 // We always need an unwinder currently for backtraces
 extern crate unwind;
 
-#[cfg(any(stage0, feature = "force_alloc_system"))]
-extern crate alloc_system;
-
 // compiler-rt intrinsics
 extern crate compiler_builtins;