diff --git a/src/test/ui/borrowck/borrowck-report-with-custom-diagnostic.rs b/src/test/ui/borrowck/borrowck-report-with-custom-diagnostic.rs
index a6553160557e..cdfee2e8a704 100644
--- a/src/test/ui/borrowck/borrowck-report-with-custom-diagnostic.rs
+++ b/src/test/ui/borrowck/borrowck-report-with-custom-diagnostic.rs
@@ -7,9 +7,9 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 #![allow(dead_code)]
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     // Original borrow ends at end of function
     let mut x = 1;
     let y = &mut x;
diff --git a/src/test/ui/borrowck/mut-borrow-outside-loop.rs b/src/test/ui/borrowck/mut-borrow-outside-loop.rs
index a1ab41bab337..edc877718ad0 100644
--- a/src/test/ui/borrowck/mut-borrow-outside-loop.rs
+++ b/src/test/ui/borrowck/mut-borrow-outside-loop.rs
@@ -9,8 +9,8 @@
 // except according to those terms.
 
 // ensure borrowck messages are correct outside special case
-
-fn main() {
+#![feature(rustc_attrs)]
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut void = ();
 
     let first = &mut void;
diff --git a/src/test/ui/codemap_tests/issue-11715.rs b/src/test/ui/codemap_tests/issue-11715.rs
index 75581d389271..03c85fbfcd77 100644
--- a/src/test/ui/codemap_tests/issue-11715.rs
+++ b/src/test/ui/codemap_tests/issue-11715.rs
@@ -93,8 +93,8 @@
 
 
 
-
-fn main() {
+#![feature(rustc_attrs)]
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut x = "foo";
     let y = &mut x;
     let z = &mut x; //~ ERROR cannot borrow
diff --git a/src/test/ui/dropck/dropck-eyepatch-extern-crate.rs b/src/test/ui/dropck/dropck-eyepatch-extern-crate.rs
index 4f88b0e6fccf..e06b47a8d79d 100644
--- a/src/test/ui/dropck/dropck-eyepatch-extern-crate.rs
+++ b/src/test/ui/dropck/dropck-eyepatch-extern-crate.rs
@@ -19,12 +19,12 @@
 //
 // See also dropck-eyepatch.rs for more information about the general
 // structure of the test.
-
+#![feature(rustc_attrs)]
 extern crate dropck_eyepatch_extern_crate as other;
 
 use other::{Dt,Dr,Pt,Pr,St,Sr};
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     use std::cell::Cell;
     let c_long;
     let (c, mut dt, mut dr, mut pt, mut pr, st, sr)
diff --git a/src/test/ui/dropck/dropck-eyepatch-reorder.rs b/src/test/ui/dropck/dropck-eyepatch-reorder.rs
index eda8d85f6ec9..832eeacbec54 100644
--- a/src/test/ui/dropck/dropck-eyepatch-reorder.rs
+++ b/src/test/ui/dropck/dropck-eyepatch-reorder.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(dropck_eyepatch)]
+#![feature(dropck_eyepatch, rustc_attrs)]
 
 // The point of this test is to test uses of `#[may_dangle]` attribute
 // where the formal declaration order (in the impl generics) does not
@@ -41,7 +41,7 @@ unsafe impl<'b, #[may_dangle] 'a, B: fmt::Debug> Drop for Pr<'a, 'b, B> {
     fn drop(&mut self) { println!("drop {} {:?}", self.0, self.2); }
 }
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     use std::cell::Cell;
     let c_long;
     let (c, mut dt, mut dr, mut pt, mut pr, st, sr)
diff --git a/src/test/ui/dropck/dropck-eyepatch.rs b/src/test/ui/dropck/dropck-eyepatch.rs
index af173a2e9791..cfa67837485e 100644
--- a/src/test/ui/dropck/dropck-eyepatch.rs
+++ b/src/test/ui/dropck/dropck-eyepatch.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(dropck_eyepatch)]
+#![feature(dropck_eyepatch, rustc_attrs)]
 
 // The point of this test is to illustrate that the `#[may_dangle]`
 // attribute specifically allows, in the context of a type
@@ -64,7 +64,7 @@ unsafe impl<#[may_dangle] 'a, 'b, B: fmt::Debug> Drop for Pr<'a, 'b, B> {
     fn drop(&mut self) { println!("drop {} {:?}", self.0, self.2); }
 }
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     use std::cell::Cell;
     let c_long;
     let (c, mut dt, mut dr, mut pt, mut pr, st, sr)
diff --git a/src/test/ui/error-codes/E0499.rs b/src/test/ui/error-codes/E0499.rs
index 9a64bfe2ea9e..c39972369347 100644
--- a/src/test/ui/error-codes/E0499.rs
+++ b/src/test/ui/error-codes/E0499.rs
@@ -7,8 +7,8 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
-fn main() {
+#![feature(rustc_attrs)]
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut i = 0;
     let mut x = &mut i;
     let mut a = &mut i; //~ ERROR E0499
diff --git a/src/test/ui/error-codes/E0502.rs b/src/test/ui/error-codes/E0502.rs
index fce8513ca64f..9c126bdcde84 100644
--- a/src/test/ui/error-codes/E0502.rs
+++ b/src/test/ui/error-codes/E0502.rs
@@ -7,12 +7,12 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 fn bar(x: &mut i32) {}
 fn foo(a: &mut i32) {
     let ref y = a;
     bar(a); //~ ERROR E0502
 }
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
 }
diff --git a/src/test/ui/error-codes/E0503.rs b/src/test/ui/error-codes/E0503.rs
index 810eb8d9b075..1822a8925d3c 100644
--- a/src/test/ui/error-codes/E0503.rs
+++ b/src/test/ui/error-codes/E0503.rs
@@ -7,8 +7,8 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
-fn main() {
+#![feature(rustc_attrs)]
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut value = 3;
     let _borrow = &mut value;
     let _sum = value + 1; //~ ERROR E0503
diff --git a/src/test/ui/error-codes/E0505.rs b/src/test/ui/error-codes/E0505.rs
index 2d534b8a44a0..dd2980936c0b 100644
--- a/src/test/ui/error-codes/E0505.rs
+++ b/src/test/ui/error-codes/E0505.rs
@@ -7,12 +7,12 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 struct Value {}
 
 fn eat(val: Value) {}
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let x = Value{};
     {
         let _ref_to_val: &Value = &x;
diff --git a/src/test/ui/error-codes/E0597.rs b/src/test/ui/error-codes/E0597.rs
index 2f4a1da91d88..74178a694440 100644
--- a/src/test/ui/error-codes/E0597.rs
+++ b/src/test/ui/error-codes/E0597.rs
@@ -7,12 +7,12 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 struct Foo<'a> {
     x: Option<&'a u32>,
 }
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut x = Foo { x: None };
     let y = 0;
     x.x = Some(&y);
diff --git a/src/test/ui/feature-gate-nll.rs b/src/test/ui/feature-gate-nll.rs
index f34a9cddf98e..752b1fa821f7 100644
--- a/src/test/ui/feature-gate-nll.rs
+++ b/src/test/ui/feature-gate-nll.rs
@@ -7,10 +7,10 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 #![allow(dead_code)]
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut x = 33;
 
     let p = &x;
diff --git a/src/test/ui/generator/borrowing.rs b/src/test/ui/generator/borrowing.rs
index e56927d81823..f80aca9fb00e 100644
--- a/src/test/ui/generator/borrowing.rs
+++ b/src/test/ui/generator/borrowing.rs
@@ -8,11 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(generators, generator_trait)]
+#![feature(generators, generator_trait, rustc_attrs)]
 
 use std::ops::Generator;
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let _b = {
         let a = 3;
         unsafe { (|| yield &a).resume() }
diff --git a/src/test/ui/generator/dropck.rs b/src/test/ui/generator/dropck.rs
index b2240fb225f5..8f4ba64fd572 100644
--- a/src/test/ui/generator/dropck.rs
+++ b/src/test/ui/generator/dropck.rs
@@ -8,12 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(generators, generator_trait, box_leak)]
+#![feature(generators, generator_trait, box_leak, rustc_attrs)]
 
 use std::cell::RefCell;
 use std::ops::Generator;
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let (cell, mut gen);
     cell = Box::new(RefCell::new(0));
     let ref_ = Box::leak(Box::new(Some(cell.borrow_mut())));
diff --git a/src/test/ui/generator/pattern-borrow.rs b/src/test/ui/generator/pattern-borrow.rs
index 557a5e62f7e4..dd63b9eaa5b1 100644
--- a/src/test/ui/generator/pattern-borrow.rs
+++ b/src/test/ui/generator/pattern-borrow.rs
@@ -8,11 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(generators)]
+#![feature(generators, rustc_attrs)]
 
 enum Test { A(i32), B, }
 
-fn main() { }
+fn main() { #![rustc_error] } // rust-lang/rust#49855
 
 fn fun(test: Test) {
     move || {
diff --git a/src/test/ui/issue-17263.rs b/src/test/ui/issue-17263.rs
index 242327e93ce1..b251f9a41525 100644
--- a/src/test/ui/issue-17263.rs
+++ b/src/test/ui/issue-17263.rs
@@ -8,11 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(box_syntax)]
+#![feature(box_syntax, rustc_attrs)]
 
 struct Foo { a: isize, b: isize }
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut x: Box<_> = box Foo { a: 1, b: 2 };
     let (a, b) = (&mut x.a, &mut x.b);
     //~^ ERROR cannot borrow `x` (via `x.b`) as mutable more than once at a time
diff --git a/src/test/ui/issue-25793.rs b/src/test/ui/issue-25793.rs
index 4f3d29216e44..8624527145c2 100644
--- a/src/test/ui/issue-25793.rs
+++ b/src/test/ui/issue-25793.rs
@@ -7,7 +7,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 macro_rules! width(
     ($this:expr) => {
         $this.width.unwrap()
@@ -29,4 +29,4 @@ impl HasInfo {
     }
 }
 
-fn main() {}
+fn main() { #![rustc_error] } // rust-lang/rust#49855
diff --git a/src/test/ui/issue-42106.rs b/src/test/ui/issue-42106.rs
index f35eee186a2a..96f410578ce5 100644
--- a/src/test/ui/issue-42106.rs
+++ b/src/test/ui/issue-42106.rs
@@ -7,10 +7,10 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 fn do_something<T>(collection: &mut Vec<T>) {
     let _a = &collection;
     collection.swap(1, 2); //~ ERROR also borrowed as immutable
 }
 
-fn main() {}
+fn main() { #![rustc_error] } // rust-lang/rust#49855
diff --git a/src/test/ui/lifetimes/borrowck-let-suggestion.rs b/src/test/ui/lifetimes/borrowck-let-suggestion.rs
index 1c904648f9e7..a7a7d5c50351 100644
--- a/src/test/ui/lifetimes/borrowck-let-suggestion.rs
+++ b/src/test/ui/lifetimes/borrowck-let-suggestion.rs
@@ -7,11 +7,11 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 fn f() {
     let x = vec![1].iter();
 }
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     f();
 }
diff --git a/src/test/ui/span/borrowck-let-suggestion-suffixes.rs b/src/test/ui/span/borrowck-let-suggestion-suffixes.rs
index 8a27af0119aa..60e6c6e29893 100644
--- a/src/test/ui/span/borrowck-let-suggestion-suffixes.rs
+++ b/src/test/ui/span/borrowck-let-suggestion-suffixes.rs
@@ -7,7 +7,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 fn id<T>(x: T) -> T { x }
 
 fn f() {
@@ -58,6 +58,6 @@ fn f() {
 //~| NOTE temporary value needs to live until here
 //~| NOTE temporary value needs to live until here
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     f();
 }
diff --git a/src/test/ui/span/issue-36537.rs b/src/test/ui/span/issue-36537.rs
index 3eac0106b18c..ca04101cf568 100644
--- a/src/test/ui/span/issue-36537.rs
+++ b/src/test/ui/span/issue-36537.rs
@@ -7,8 +7,8 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
-fn main() {
+#![feature(rustc_attrs)]
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let p;
     let a = 42;
     p = &a;
diff --git a/src/test/ui/span/mut-ptr-cant-outlive-ref.rs b/src/test/ui/span/mut-ptr-cant-outlive-ref.rs
index 9dc0836c5e06..9774303197c5 100644
--- a/src/test/ui/span/mut-ptr-cant-outlive-ref.rs
+++ b/src/test/ui/span/mut-ptr-cant-outlive-ref.rs
@@ -7,10 +7,10 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 use std::cell::RefCell;
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let m = RefCell::new(0);
     let p;
     {
diff --git a/src/test/ui/span/range-2.rs b/src/test/ui/span/range-2.rs
index d69b3ea098cb..a1ed9bc6aa84 100644
--- a/src/test/ui/span/range-2.rs
+++ b/src/test/ui/span/range-2.rs
@@ -9,8 +9,8 @@
 // except according to those terms.
 
 // Test range syntax - borrow errors.
-
-pub fn main() {
+#![feature(rustc_attrs)]
+pub fn main() { #![rustc_error] // rust-lang/rust#49855
     let r = {
         let a = 42;
         let b = 42;
diff --git a/src/test/ui/span/regionck-unboxed-closure-lifetimes.rs b/src/test/ui/span/regionck-unboxed-closure-lifetimes.rs
index 93b3d6733598..c814941c8112 100644
--- a/src/test/ui/span/regionck-unboxed-closure-lifetimes.rs
+++ b/src/test/ui/span/regionck-unboxed-closure-lifetimes.rs
@@ -7,10 +7,10 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 use std::ops::FnMut;
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut f;
     {
         let c = 1;
diff --git a/src/test/ui/span/slice-borrow.rs b/src/test/ui/span/slice-borrow.rs
index 1b022f232466..45dff62672be 100644
--- a/src/test/ui/span/slice-borrow.rs
+++ b/src/test/ui/span/slice-borrow.rs
@@ -7,10 +7,10 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
+#![feature(rustc_attrs)]
 // Test slicing expressions doesn't defeat the borrow checker.
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let y;
     {
         let x: &[isize] = &vec![1, 2, 3, 4, 5];
diff --git a/src/test/ui/span/vec_refs_data_with_early_death.rs b/src/test/ui/span/vec_refs_data_with_early_death.rs
index 42373a87a6c9..a3532d919bc0 100644
--- a/src/test/ui/span/vec_refs_data_with_early_death.rs
+++ b/src/test/ui/span/vec_refs_data_with_early_death.rs
@@ -17,8 +17,8 @@
 //  element it owns; thus, for data like this, it seems like we could
 //  loosen the restrictions here if we wanted. But it also is not
 //  clear whether such loosening is terribly important.)
-
-fn main() {
+#![feature(rustc_attrs)]
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let mut v = Vec::new();
 
     let x: i8 = 3;
diff --git a/src/test/ui/span/wf-method-late-bound-regions.rs b/src/test/ui/span/wf-method-late-bound-regions.rs
index d58c29d4a32d..317cd395d0a7 100644
--- a/src/test/ui/span/wf-method-late-bound-regions.rs
+++ b/src/test/ui/span/wf-method-late-bound-regions.rs
@@ -11,7 +11,7 @@
 // A method's receiver must be well-formed, even if it has late-bound regions.
 // Because of this, a method's substs being well-formed does not imply that
 // the method's implied bounds are met.
-
+#![feature(rustc_attrs)]
 struct Foo<'b>(Option<&'b ()>);
 
 trait Bar<'b> {
@@ -22,7 +22,7 @@ impl<'b> Bar<'b> for Foo<'b> {
     fn xmute<'a>(&'a self, u: &'b u32) -> &'a u32 { u }
 }
 
-fn main() {
+fn main() { #![rustc_error] // rust-lang/rust#49855
     let f = Foo(None);
     let f2 = f;
     let dangling = {