diff -aur rustc-1.50.0-src/compiler/rustc_error_codes/src/error_codes/E0778.md rustc-1.50.0-src_patched/compiler/rustc_error_codes/src/error_codes/E0778.md
--- rustc-1.50.0-src/compiler/rustc_error_codes/src/error_codes/E0778.md	2021-03-25 00:27:25.008531043 +0100
+++ rustc-1.50.0-src_patched/compiler/rustc_error_codes/src/error_codes/E0778.md	2021-03-25 00:26:52.956757363 +0100
@@ -13,7 +13,7 @@
 The parenthesized `instruction_set` attribute requires the parameter to be
 specified:
 
-```
+```allow_fail
 #![feature(isa_attribute)]
 
 #[cfg_attr(target_arch="arm", instruction_set(arm::a32))]
@@ -22,7 +22,7 @@
 
 or:
 
-```
+```allow_fail
 #![feature(isa_attribute)]
 
 #[cfg_attr(target_arch="arm", instruction_set(arm::t32))]
diff -aur rustc-1.50.0-src/compiler/rustc_error_codes/src/error_codes/E0779.md rustc-1.50.0-src_patched/compiler/rustc_error_codes/src/error_codes/E0779.md
--- rustc-1.50.0-src/compiler/rustc_error_codes/src/error_codes/E0779.md	2021-03-25 00:27:32.300441475 +0100
+++ rustc-1.50.0-src_patched/compiler/rustc_error_codes/src/error_codes/E0779.md	2021-03-25 00:26:52.957757363 +0100
@@ -18,7 +18,7 @@
 All other arguments given to the `instruction_set` attribute will return this
 error. Example:
 
-```
+```allow_fail
 #![feature(isa_attribute)]
 
 #[cfg_attr(target_arch="arm", instruction_set(arm::a32))] // ok!