diff --git a/src/tools/run-make-support/src/command.rs b/src/tools/run-make-support/src/command.rs
index 7cbc61bdf33e8..dab18dca2ff99 100644
--- a/src/tools/run-make-support/src/command.rs
+++ b/src/tools/run-make-support/src/command.rs
@@ -6,7 +6,7 @@ use std::path::Path;
 use std::process::{Command as StdCommand, ExitStatus, Output, Stdio};
 
 use crate::drop_bomb::DropBomb;
-use crate::{assert_not_contains, handle_failed_output};
+use crate::{assert_contains, assert_not_contains, handle_failed_output};
 
 /// This is a custom command wrapper that simplifies working with commands and makes it easier to
 /// ensure that we check the exit status of executed processes.
@@ -170,6 +170,12 @@ impl CompletedProcess {
         self
     }
 
+    #[track_caller]
+    pub fn assert_stdout_contains<S: AsRef<str>>(self, needle: S) -> Self {
+        assert_contains(&self.stdout_utf8(), needle.as_ref());
+        self
+    }
+
     #[track_caller]
     pub fn assert_stdout_not_contains<S: AsRef<str>>(&self, needle: S) -> &Self {
         assert_not_contains(&self.stdout_utf8(), needle.as_ref());
@@ -185,7 +191,7 @@ impl CompletedProcess {
 
     #[track_caller]
     pub fn assert_stderr_contains<S: AsRef<str>>(&self, needle: S) -> &Self {
-        assert!(self.stderr_utf8().contains(needle.as_ref()));
+        assert_contains(&self.stderr_utf8(), needle.as_ref());
         self
     }
 
diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index d077c500c5d76..ba4524c150c46 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -332,6 +332,18 @@ pub fn read_dir<F: Fn(&Path)>(dir: impl AsRef<Path>, callback: F) {
     }
 }
 
+/// Check that `haystack` contains `needle`. Panic otherwise.
+#[track_caller]
+pub fn assert_contains(haystack: &str, needle: &str) {
+    if !haystack.contains(needle) {
+        eprintln!("=== HAYSTACK ===");
+        eprintln!("{}", haystack);
+        eprintln!("=== NEEDLE ===");
+        eprintln!("{}", needle);
+        panic!("needle was not found in haystack");
+    }
+}
+
 /// Check that `haystack` does not contain `needle`. Panic otherwise.
 #[track_caller]
 pub fn assert_not_contains(haystack: &str, needle: &str) {
diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index 37da5d9c88d90..280420d022d66 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -1,5 +1,4 @@
 run-make/allocator-shim-circular-deps/Makefile
-run-make/allow-non-lint-warnings-cmdline/Makefile
 run-make/archive-duplicate-names/Makefile
 run-make/atomic-lock-free/Makefile
 run-make/branch-protection-check-IBT/Makefile
diff --git a/tests/run-make/allow-non-lint-warnings-cmdline/Makefile b/tests/run-make/allow-non-lint-warnings-cmdline/Makefile
deleted file mode 100644
index 78b9a7b989895..0000000000000
--- a/tests/run-make/allow-non-lint-warnings-cmdline/Makefile
+++ /dev/null
@@ -1,12 +0,0 @@
-# ignore-cross-compile
-include ../tools.mk
-
-# Test that -A warnings makes the 'empty trait list for derive' warning go away
-OUT=$(shell $(RUSTC) foo.rs -A warnings 2>&1 | grep "warning" )
-
-all: foo
-	test -z '$(OUT)'
-
-# This is just to make sure the above command actually succeeds
-foo:
-	$(RUSTC) foo.rs -A warnings
diff --git a/tests/run-make/allow-non-lint-warnings-cmdline/foo.rs b/tests/ui/allow-non-lint-warnings.rs
similarity index 60%
rename from tests/run-make/allow-non-lint-warnings-cmdline/foo.rs
rename to tests/ui/allow-non-lint-warnings.rs
index 02e8ccabf7921..f8f5a78ebff26 100644
--- a/tests/run-make/allow-non-lint-warnings-cmdline/foo.rs
+++ b/tests/ui/allow-non-lint-warnings.rs
@@ -1,3 +1,6 @@
+//@ compile-flags: -Awarnings
+//@ check-pass
+
 #[derive()]
 #[derive(Copy, Clone)]
 pub struct Foo;