From 86e81f9926ad52b79397d037cf6e0392fb6f0db2 Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Wed, 14 Jun 2023 20:17:12 +0000
Subject: [PATCH 1/9] Add --exact flag

---
 kani-driver/src/args/mod.rs                   |  4 +
 kani-driver/src/metadata.rs                   | 90 ++++++++++++++++---
 .../check-qualified-name/expected             |  2 +
 .../select_harness_with_module.rs             | 22 +++++
 tests/ui/exact-harness/check_some/expected    |  3 +
 .../check_some/select_harnesses.rs            | 19 ++++
 .../incomplete-harness-name/expected          |  1 +
 .../incomplete_harness.rs                     | 22 +++++
 .../exact-harness/multiple_matches/expected   |  3 +
 .../select_multiple_harnesses.rs              | 39 ++++++++
 .../some_matching_harnesses/expected          |  2 +
 .../some_matching_harnesses/subset.rs         | 39 ++++++++
 12 files changed, 233 insertions(+), 13 deletions(-)
 create mode 100644 tests/ui/exact-harness/check-qualified-name/expected
 create mode 100644 tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
 create mode 100644 tests/ui/exact-harness/check_some/expected
 create mode 100644 tests/ui/exact-harness/check_some/select_harnesses.rs
 create mode 100644 tests/ui/exact-harness/incomplete-harness-name/expected
 create mode 100644 tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
 create mode 100644 tests/ui/exact-harness/multiple_matches/expected
 create mode 100644 tests/ui/exact-harness/multiple_matches/select_multiple_harnesses.rs
 create mode 100644 tests/ui/exact-harness/some_matching_harnesses/expected
 create mode 100644 tests/ui/exact-harness/some_matching_harnesses/subset.rs

diff --git a/kani-driver/src/args/mod.rs b/kani-driver/src/args/mod.rs
index dbc80fedbb99..97cd33dc8f69 100644
--- a/kani-driver/src/args/mod.rs
+++ b/kani-driver/src/args/mod.rs
@@ -177,6 +177,10 @@ pub struct VerificationArgs {
     )]
     pub harnesses: Vec<String>,
 
+    /// If specified, with the fully qualified name of the harness provided, runs that specific harness and nothing more
+    #[arg(long, requires("harnesses"))]
+    pub exact: bool,
+
     /// Link external C files referenced by Rust code.
     /// This is an experimental feature and requires `-Z c-ffi` to be used
     #[arg(long, hide = true, num_args(1..))]
diff --git a/kani-driver/src/metadata.rs b/kani-driver/src/metadata.rs
index 613129d8188c..54dea2e55d51 100644
--- a/kani-driver/src/metadata.rs
+++ b/kani-driver/src/metadata.rs
@@ -124,7 +124,8 @@ impl KaniSession {
         if harnesses.is_empty() {
             Ok(Vec::from(all_harnesses))
         } else {
-            let harnesses = find_proof_harnesses(harnesses, all_harnesses);
+            let harnesses: Vec<&HarnessMetadata> =
+                find_proof_harnesses(harnesses, all_harnesses, self.args.exact);
             Ok(harnesses)
         }
     }
@@ -169,18 +170,29 @@ pub fn mock_proof_harness(
 fn find_proof_harnesses<'a>(
     targets: BTreeSet<&String>,
     all_harnesses: &[&'a HarnessMetadata],
+    exact_filter: bool,
 ) -> Vec<&'a HarnessMetadata> {
     debug!(?targets, "find_proof_harness");
     let mut result = vec![];
     for md in all_harnesses.iter() {
-        // Either an exact match, or a substring match. We check the exact first since it's cheaper.
-        if targets.contains(&md.pretty_name)
-            || targets.contains(&md.get_harness_name_unqualified().to_string())
-            || targets.iter().any(|target| md.pretty_name.contains(*target))
-        {
-            result.push(*md);
+        // Check for exact match only
+        if exact_filter {
+            if targets.contains(&md.pretty_name) {
+                // if exact match found, stop searching
+                result.push(*md);
+            } else {
+                trace!(skip = md.pretty_name, "find_proof_harnesses");
+            }
         } else {
-            trace!(skip = md.pretty_name, "find_proof_harnesses");
+            // Either an exact match, or a substring match. We check the exact first since it's cheaper.
+            if targets.contains(&md.pretty_name)
+                || targets.contains(&md.get_harness_name_unqualified().to_string())
+                || targets.iter().any(|target| md.pretty_name.contains(*target))
+            {
+                result.push(*md);
+            } else {
+                trace!(skip = md.pretty_name, "find_proof_harnesses");
+            }
         }
     }
     result
@@ -191,31 +203,83 @@ mod tests {
     use super::*;
 
     #[test]
-    fn check_find_proof_harness() {
+    fn check_find_proof_harness_without_exact() {
         let harnesses = vec![
             mock_proof_harness("check_one", None, None, None),
             mock_proof_harness("module::check_two", None, None, None),
             mock_proof_harness("module::not_check_three", None, None, None),
         ];
         let ref_harnesses = harnesses.iter().collect::<Vec<_>>();
+
+        // Check with harness filtering
         assert_eq!(
-            find_proof_harnesses(BTreeSet::from([&"check_three".to_string()]), &ref_harnesses)
-                .len(),
+            find_proof_harnesses(
+                BTreeSet::from([&"check_three".to_string()]),
+                &ref_harnesses,
+                false
+            )
+            .len(),
             1
         );
         assert!(
-            find_proof_harnesses(BTreeSet::from([&"check_two".to_string()]), &ref_harnesses)
+            find_proof_harnesses(BTreeSet::from([&"check_two".to_string()]), &ref_harnesses, false)
                 .first()
                 .unwrap()
                 .mangled_name
                 == "module::check_two"
         );
         assert!(
-            find_proof_harnesses(BTreeSet::from([&"check_one".to_string()]), &ref_harnesses)
+            find_proof_harnesses(BTreeSet::from([&"check_one".to_string()]), &ref_harnesses, false)
                 .first()
                 .unwrap()
                 .mangled_name
                 == "check_one"
         );
+
+        // Check with exact match
+        assert_eq!(
+            find_proof_harnesses(
+                BTreeSet::from([&"check_three".to_string()]),
+                &ref_harnesses,
+                true
+            )
+            .len(),
+            0
+        );
+        assert_eq!(
+            find_proof_harnesses(BTreeSet::from([&"check_two".to_string()]), &ref_harnesses, true)
+                .first()
+                .is_none(),
+            true
+        );
+        assert_eq!(
+            find_proof_harnesses(BTreeSet::from([&"check_one".to_string()]), &ref_harnesses, true)
+                .first()
+                .unwrap()
+                .mangled_name,
+            "check_one"
+        );
+        assert_ne!(
+            find_proof_harnesses(
+                BTreeSet::from([&"module::not_check_three".to_string()]),
+                &ref_harnesses,
+                true
+            )
+            .first()
+            .unwrap()
+            .mangled_name,
+            "not_check_three"
+        );
+        assert_eq!(
+            find_proof_harnesses(
+                BTreeSet::from([&"module::not_check_three".to_string()]),
+                &ref_harnesses,
+                true
+            )
+            .first()
+            .unwrap()
+            .mangled_name,
+            "module::not_check_three"
+        );
     }
 }
diff --git a/tests/ui/exact-harness/check-qualified-name/expected b/tests/ui/exact-harness/check-qualified-name/expected
new file mode 100644
index 000000000000..f8295f7a0c73
--- /dev/null
+++ b/tests/ui/exact-harness/check-qualified-name/expected
@@ -0,0 +1,2 @@
+Checking harness first::check_foo...
+VERIFICATION:- SUCCESSFUL
diff --git a/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs b/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
new file mode 100644
index 000000000000..981472f67a9c
--- /dev/null
+++ b/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
@@ -0,0 +1,22 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+// kani-flags: --harness first::check_foo --exact
+//! Ensure that the set of harnesses run is the union of all arguments.
+
+mod first {
+    #[kani::proof]
+    fn check_foo() {
+        assert!(1 == 1);
+    }
+
+    #[kani::proof]
+    fn check_blah() {
+        assert!(2 == 2);
+    }
+
+    /// A harness that will fail verification if it is run.
+    #[kani::proof]
+    fn ignore_third_harness() {
+        assert!(3 == 2);
+    }
+}
diff --git a/tests/ui/exact-harness/check_some/expected b/tests/ui/exact-harness/check_some/expected
new file mode 100644
index 000000000000..875c01a46612
--- /dev/null
+++ b/tests/ui/exact-harness/check_some/expected
@@ -0,0 +1,3 @@
+Checking harness check_second_harness...
+Checking harness check_first_harness...
+Complete - 2 successfully verified harnesses, 0 failures, 2 total.
diff --git a/tests/ui/exact-harness/check_some/select_harnesses.rs b/tests/ui/exact-harness/check_some/select_harnesses.rs
new file mode 100644
index 000000000000..0ac125fde552
--- /dev/null
+++ b/tests/ui/exact-harness/check_some/select_harnesses.rs
@@ -0,0 +1,19 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+// kani-flags: --harness check_first_harness --harness check_second_harness --exact
+//! Ensure that we can select multiple harnesses at a time.
+#[kani::proof]
+fn check_first_harness() {
+    assert!(1 == 1);
+}
+
+#[kani::proof]
+fn check_second_harness() {
+    assert!(2 == 2);
+}
+
+/// A harness that will fail verification if it is run.
+#[kani::proof]
+fn ignore_third_harness() {
+    assert!(3 == 2);
+}
diff --git a/tests/ui/exact-harness/incomplete-harness-name/expected b/tests/ui/exact-harness/incomplete-harness-name/expected
new file mode 100644
index 000000000000..8cf6d54f0a28
--- /dev/null
+++ b/tests/ui/exact-harness/incomplete-harness-name/expected
@@ -0,0 +1 @@
+error: no harnesses matched the harness filter: `check_blah`
diff --git a/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs b/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
new file mode 100644
index 000000000000..d73137d1f04f
--- /dev/null
+++ b/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
@@ -0,0 +1,22 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+// kani-flags: --harness check_blah --exact
+//! Check that we just ignore non-matching filters
+
+mod first {
+    #[kani::proof]
+    fn check_foo() {
+        assert!(1 == 1);
+    }
+
+    #[kani::proof]
+    fn check_blah() {
+        assert!(2 == 2);
+    }
+
+    /// A harness that will fail verification if it is run.
+    #[kani::proof]
+    fn ignore_third_harness() {
+        assert!(3 == 2);
+    }
+}
diff --git a/tests/ui/exact-harness/multiple_matches/expected b/tests/ui/exact-harness/multiple_matches/expected
new file mode 100644
index 000000000000..8c2420d08c77
--- /dev/null
+++ b/tests/ui/exact-harness/multiple_matches/expected
@@ -0,0 +1,3 @@
+Checking harness second::verify_foo...
+Checking harness first::check_blah...
+Complete - 2 successfully verified harnesses, 0 failures, 2 total.
diff --git a/tests/ui/exact-harness/multiple_matches/select_multiple_harnesses.rs b/tests/ui/exact-harness/multiple_matches/select_multiple_harnesses.rs
new file mode 100644
index 000000000000..5a49072dce17
--- /dev/null
+++ b/tests/ui/exact-harness/multiple_matches/select_multiple_harnesses.rs
@@ -0,0 +1,39 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+// kani-flags: --harness first::check_blah --exact --harness second::verify_foo
+//! Ensure that the set of harnesses run is the union of all arguments.
+
+mod first {
+    #[kani::proof]
+    fn check_foo() {
+        assert!(1 == 1);
+    }
+
+    #[kani::proof]
+    fn check_blah() {
+        assert!(2 == 2);
+    }
+
+    /// A harness that will fail verification if it is run.
+    #[kani::proof]
+    fn ignore_third_harness() {
+        assert!(3 == 2);
+    }
+}
+
+mod second {
+    #[kani::proof]
+    fn verify_foo() {
+        assert!(1 == 1);
+    }
+
+    #[kani::proof]
+    fn verify_blah() {
+        assert!(2 == 2);
+    }
+
+    #[kani::proof]
+    fn verify_harness() {
+        assert!(3 == 3);
+    }
+}
diff --git a/tests/ui/exact-harness/some_matching_harnesses/expected b/tests/ui/exact-harness/some_matching_harnesses/expected
new file mode 100644
index 000000000000..e3401ff858c2
--- /dev/null
+++ b/tests/ui/exact-harness/some_matching_harnesses/expected
@@ -0,0 +1,2 @@
+Checking harness existing...
+VERIFICATION:- SUCCESSFUL
diff --git a/tests/ui/exact-harness/some_matching_harnesses/subset.rs b/tests/ui/exact-harness/some_matching_harnesses/subset.rs
new file mode 100644
index 000000000000..7b7ed5358889
--- /dev/null
+++ b/tests/ui/exact-harness/some_matching_harnesses/subset.rs
@@ -0,0 +1,39 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+// kani-flags: --harness existing --harness check_blah --exact
+//! Check that we just ignore non-matching filters
+
+mod first {
+    #[kani::proof]
+    fn check_foo() {
+        assert!(1 == 1);
+    }
+
+    #[kani::proof]
+    fn check_blah() {
+        assert!(2 == 2);
+    }
+
+    /// A harness that will fail verification if it is run.
+    #[kani::proof]
+    fn ignore_third_harness() {
+        assert!(3 == 2);
+    }
+}
+
+// This harness will be picked up
+#[kani::proof]
+fn existing() {
+    assert!(1 == 1);
+}
+
+#[kani::proof]
+fn existing_harness() {
+    assert!(2 == 2);
+}
+
+/// A harness that will fail verification if it is run.
+#[kani::proof]
+fn ignored_harness() {
+    assert!(3 == 2);
+}

From 00a367fcb325dfd411204607c01034c0163e3b70 Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Thu, 15 Jun 2023 20:39:00 +0000
Subject: [PATCH 2/9] Add completion status to single harness, and address PR
 feedback

---
 kani-driver/src/args/mod.rs                   |  1 +
 kani-driver/src/harness_runner.rs             | 22 ++++++++----
 kani-driver/src/metadata.rs                   | 35 +++++++++----------
 .../check_summary_for_single_harness/expected |  2 ++
 .../single_harness.rs                         |  9 +++++
 .../check-qualified-name/expected             |  2 +-
 .../select_harness_with_module.rs             |  2 +-
 .../check_substring_not_matching/expected     |  2 ++
 .../select_harness_with_module.rs             | 23 ++++++++++++
 .../incomplete-harness-name/expected          |  2 +-
 .../select_multiple_harnesses.rs              |  2 +-
 .../some_matching_harnesses/expected          |  1 +
 .../some_matching_harnesses/subset.rs         |  4 +--
 13 files changed, 76 insertions(+), 31 deletions(-)
 create mode 100644 tests/ui/check_summary_for_single_harness/expected
 create mode 100644 tests/ui/check_summary_for_single_harness/single_harness.rs
 create mode 100644 tests/ui/exact-harness/check_substring_not_matching/expected
 create mode 100644 tests/ui/exact-harness/check_substring_not_matching/select_harness_with_module.rs

diff --git a/kani-driver/src/args/mod.rs b/kani-driver/src/args/mod.rs
index 97cd33dc8f69..44a09197be5c 100644
--- a/kani-driver/src/args/mod.rs
+++ b/kani-driver/src/args/mod.rs
@@ -169,6 +169,7 @@ pub struct VerificationArgs {
     pub function: Option<String>,
     /// If specified, only run harnesses that match this filter. This option can be provided
     /// multiple times, which will run all tests matching any of the filters.
+    /// If used with --exact, the filter is removed and only exact matches are run.
     #[arg(
         long = "harness",
         conflicts_with = "function",
diff --git a/kani-driver/src/harness_runner.rs b/kani-driver/src/harness_runner.rs
index f1f0befc4ddd..a5bd69e3390a 100644
--- a/kani-driver/src/harness_runner.rs
+++ b/kani-driver/src/harness_runner.rs
@@ -154,7 +154,7 @@ impl KaniSession {
         }
 
         // We currently omit a summary if there was just 1 harness
-        if !self.args.common_args.quiet && !self.args.visualize && total != 1 {
+        if !self.args.common_args.quiet && !self.args.visualize {
             if failing > 0 {
                 println!("Summary:");
             }
@@ -177,12 +177,22 @@ impl KaniSession {
                         )
                     }
                     ([harness], None) => {
-                        bail!("no harnesses matched the harness filter: `{harness}`")
+                        if !self.args.exact {
+                            bail!("no harnesses matched the harness filter: `{harness}`")
+                        } else {
+                            bail!("no harnesses matched the name: `{harness}`")
+                        }
+                    }
+                    (harnesses, None) => {
+                        if !self.args.exact {
+                            bail!(
+                                "no harnesses matched the harness filters: `{}`",
+                                harnesses.join("`, `")
+                            )
+                        } else {
+                            bail!("no harnesses matched the names: `{}`", harnesses.join("`, `"))
+                        }
                     }
-                    (harnesses, None) => bail!(
-                        "no harnesses matched the harness filters: `{}`",
-                        harnesses.join("`, `")
-                    ),
                     ([], Some(func)) => error(&format!("No function named {func} was found")),
                     _ => unreachable!(
                         "invalid configuration. Cannot specify harness and function at the same time"
diff --git a/kani-driver/src/metadata.rs b/kani-driver/src/metadata.rs
index 54dea2e55d51..8d9bc24ae226 100644
--- a/kani-driver/src/metadata.rs
+++ b/kani-driver/src/metadata.rs
@@ -175,8 +175,8 @@ fn find_proof_harnesses<'a>(
     debug!(?targets, "find_proof_harness");
     let mut result = vec![];
     for md in all_harnesses.iter() {
-        // Check for exact match only
         if exact_filter {
+            // Check for exact match only
             if targets.contains(&md.pretty_name) {
                 // if exact match found, stop searching
                 result.push(*md);
@@ -235,22 +235,30 @@ mod tests {
                 .mangled_name
                 == "check_one"
         );
+    }
 
+    #[test]
+    fn check_find_proof_harness_with_exact() {
         // Check with exact match
-        assert_eq!(
+
+        let harnesses = vec![
+            mock_proof_harness("check_one", None, None, None),
+            mock_proof_harness("module::check_two", None, None, None),
+            mock_proof_harness("module::not_check_three", None, None, None),
+        ];
+        let ref_harnesses = harnesses.iter().collect::<Vec<_>>();
+
+        assert!(
             find_proof_harnesses(
                 BTreeSet::from([&"check_three".to_string()]),
                 &ref_harnesses,
                 true
             )
-            .len(),
-            0
+            .is_empty()
         );
-        assert_eq!(
+        assert!(
             find_proof_harnesses(BTreeSet::from([&"check_two".to_string()]), &ref_harnesses, true)
-                .first()
-                .is_none(),
-            true
+                .is_empty()
         );
         assert_eq!(
             find_proof_harnesses(BTreeSet::from([&"check_one".to_string()]), &ref_harnesses, true)
@@ -259,17 +267,6 @@ mod tests {
                 .mangled_name,
             "check_one"
         );
-        assert_ne!(
-            find_proof_harnesses(
-                BTreeSet::from([&"module::not_check_three".to_string()]),
-                &ref_harnesses,
-                true
-            )
-            .first()
-            .unwrap()
-            .mangled_name,
-            "not_check_three"
-        );
         assert_eq!(
             find_proof_harnesses(
                 BTreeSet::from([&"module::not_check_three".to_string()]),
diff --git a/tests/ui/check_summary_for_single_harness/expected b/tests/ui/check_summary_for_single_harness/expected
new file mode 100644
index 000000000000..17aaa37eee0c
--- /dev/null
+++ b/tests/ui/check_summary_for_single_harness/expected
@@ -0,0 +1,2 @@
+Checking harness check_foo...
+Complete - 1 successfully verified harnesses, 0 failures, 1 total.
diff --git a/tests/ui/check_summary_for_single_harness/single_harness.rs b/tests/ui/check_summary_for_single_harness/single_harness.rs
new file mode 100644
index 000000000000..3d032881d446
--- /dev/null
+++ b/tests/ui/check_summary_for_single_harness/single_harness.rs
@@ -0,0 +1,9 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+// kani-flags: --harness check_foo --exact
+//! Check for the summary line at the end of the verification output
+
+#[kani::proof]
+fn check_foo() {
+    assert!(1 == 1);
+}
diff --git a/tests/ui/exact-harness/check-qualified-name/expected b/tests/ui/exact-harness/check-qualified-name/expected
index f8295f7a0c73..458e90d9d2de 100644
--- a/tests/ui/exact-harness/check-qualified-name/expected
+++ b/tests/ui/exact-harness/check-qualified-name/expected
@@ -1,2 +1,2 @@
 Checking harness first::check_foo...
-VERIFICATION:- SUCCESSFUL
+Complete - 1 successfully verified harnesses, 0 failures, 1 total.
diff --git a/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs b/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
index 981472f67a9c..63ad24196127 100644
--- a/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
+++ b/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
@@ -1,7 +1,7 @@
 // Copyright Kani Contributors
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 // kani-flags: --harness first::check_foo --exact
-//! Ensure that the set of harnesses run is the union of all arguments.
+//! Ensure that only the specified harness is run
 
 mod first {
     #[kani::proof]
diff --git a/tests/ui/exact-harness/check_substring_not_matching/expected b/tests/ui/exact-harness/check_substring_not_matching/expected
new file mode 100644
index 000000000000..50b34e8d0b2d
--- /dev/null
+++ b/tests/ui/exact-harness/check_substring_not_matching/expected
@@ -0,0 +1,2 @@
+Checking harness first::harness...
+VERIFICATION:- SUCCESSFUL
diff --git a/tests/ui/exact-harness/check_substring_not_matching/select_harness_with_module.rs b/tests/ui/exact-harness/check_substring_not_matching/select_harness_with_module.rs
new file mode 100644
index 000000000000..f46deb719f74
--- /dev/null
+++ b/tests/ui/exact-harness/check_substring_not_matching/select_harness_with_module.rs
@@ -0,0 +1,23 @@
+// Copyright Kani Contributors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+// kani-flags: --harness first::harness --exact
+//! Ensure that only the harness specified with --exact is picked up
+
+mod first {
+    #[kani::proof]
+    fn harness() {
+        assert!(1 == 1);
+    }
+
+    /// A harness that will fail verification if it is picked up.
+    #[kani::proof]
+    fn harness_1() {
+        assert!(1 == 2);
+    }
+
+    /// A harness that will fail verification if it is picked up.
+    #[kani::proof]
+    fn harness_2() {
+        assert!(3 == 2);
+    }
+}
diff --git a/tests/ui/exact-harness/incomplete-harness-name/expected b/tests/ui/exact-harness/incomplete-harness-name/expected
index 8cf6d54f0a28..b1cca2c68b25 100644
--- a/tests/ui/exact-harness/incomplete-harness-name/expected
+++ b/tests/ui/exact-harness/incomplete-harness-name/expected
@@ -1 +1 @@
-error: no harnesses matched the harness filter: `check_blah`
+error: no harnesses matched the name: `check_blah`
diff --git a/tests/ui/exact-harness/multiple_matches/select_multiple_harnesses.rs b/tests/ui/exact-harness/multiple_matches/select_multiple_harnesses.rs
index 5a49072dce17..68aa59fbfa69 100644
--- a/tests/ui/exact-harness/multiple_matches/select_multiple_harnesses.rs
+++ b/tests/ui/exact-harness/multiple_matches/select_multiple_harnesses.rs
@@ -1,7 +1,7 @@
 // Copyright Kani Contributors
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 // kani-flags: --harness first::check_blah --exact --harness second::verify_foo
-//! Ensure that the set of harnesses run is the union of all arguments.
+//! Ensure that only the specified harnesses are run
 
 mod first {
     #[kani::proof]
diff --git a/tests/ui/exact-harness/some_matching_harnesses/expected b/tests/ui/exact-harness/some_matching_harnesses/expected
index e3401ff858c2..45a411f32c0d 100644
--- a/tests/ui/exact-harness/some_matching_harnesses/expected
+++ b/tests/ui/exact-harness/some_matching_harnesses/expected
@@ -1,2 +1,3 @@
 Checking harness existing...
 VERIFICATION:- SUCCESSFUL
+Complete - 1 successfully verified harnesses, 0 failures, 1 total.
diff --git a/tests/ui/exact-harness/some_matching_harnesses/subset.rs b/tests/ui/exact-harness/some_matching_harnesses/subset.rs
index 7b7ed5358889..02d14c39d1c7 100644
--- a/tests/ui/exact-harness/some_matching_harnesses/subset.rs
+++ b/tests/ui/exact-harness/some_matching_harnesses/subset.rs
@@ -6,7 +6,7 @@
 mod first {
     #[kani::proof]
     fn check_foo() {
-        assert!(1 == 1);
+        assert!(1 == 2);
     }
 
     #[kani::proof]
@@ -29,7 +29,7 @@ fn existing() {
 
 #[kani::proof]
 fn existing_harness() {
-    assert!(2 == 2);
+    assert!(1 == 2);
 }
 
 /// A harness that will fail verification if it is run.

From 2bbf0f80ea2fcb7802cc9c6c8c0c9a4f170a4ba1 Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Thu, 15 Jun 2023 20:43:29 +0000
Subject: [PATCH 3/9] Add doc comments

---
 kani-driver/src/args/mod.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kani-driver/src/args/mod.rs b/kani-driver/src/args/mod.rs
index 44a09197be5c..31cae95e2a61 100644
--- a/kani-driver/src/args/mod.rs
+++ b/kani-driver/src/args/mod.rs
@@ -169,7 +169,7 @@ pub struct VerificationArgs {
     pub function: Option<String>,
     /// If specified, only run harnesses that match this filter. This option can be provided
     /// multiple times, which will run all tests matching any of the filters.
-    /// If used with --exact, the filter is removed and only exact matches are run.
+    /// If used with --exact, the harness filter will only match the exact fully qualified name of a harness.
     #[arg(
         long = "harness",
         conflicts_with = "function",
@@ -178,7 +178,7 @@ pub struct VerificationArgs {
     )]
     pub harnesses: Vec<String>,
 
-    /// If specified, with the fully qualified name of the harness provided, runs that specific harness and nothing more
+    /// When specified, the harness filter will only match the exact fully qualified name of a harness
     #[arg(long, requires("harnesses"))]
     pub exact: bool,
 

From 85936fe35efdfb1b6dfc478cb988846b01fc6b0f Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Thu, 15 Jun 2023 21:03:48 +0000
Subject: [PATCH 4/9] Add summary to tests

---
 tests/ui/exact-harness/check-qualified-name/expected           | 1 +
 .../check-qualified-name/select_harness_with_module.rs         | 3 ++-
 tests/ui/exact-harness/check_substring_not_matching/expected   | 2 ++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/tests/ui/exact-harness/check-qualified-name/expected b/tests/ui/exact-harness/check-qualified-name/expected
index 458e90d9d2de..59ff06ae136d 100644
--- a/tests/ui/exact-harness/check-qualified-name/expected
+++ b/tests/ui/exact-harness/check-qualified-name/expected
@@ -1,2 +1,3 @@
 Checking harness first::check_foo...
+VERIFICATION:- SUCCESSFUL
 Complete - 1 successfully verified harnesses, 0 failures, 1 total.
diff --git a/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs b/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
index 63ad24196127..9269b93afa37 100644
--- a/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
+++ b/tests/ui/exact-harness/check-qualified-name/select_harness_with_module.rs
@@ -9,9 +9,10 @@ mod first {
         assert!(1 == 1);
     }
 
+    /// A harness that will fail verification if it is run.
     #[kani::proof]
     fn check_blah() {
-        assert!(2 == 2);
+        assert!(1 == 2);
     }
 
     /// A harness that will fail verification if it is run.
diff --git a/tests/ui/exact-harness/check_substring_not_matching/expected b/tests/ui/exact-harness/check_substring_not_matching/expected
index 50b34e8d0b2d..6db88e2b537f 100644
--- a/tests/ui/exact-harness/check_substring_not_matching/expected
+++ b/tests/ui/exact-harness/check_substring_not_matching/expected
@@ -1,2 +1,4 @@
 Checking harness first::harness...
 VERIFICATION:- SUCCESSFUL
+Complete - 1 successfully verified harnesses, 0 failures, 1 total.
+

From cd72692f5ca7f8a9c75e2b6b46a48314cc0e781f Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Fri, 16 Jun 2023 19:51:50 +0000
Subject: [PATCH 5/9] Add failure on any exact match failing

---
 kani-driver/src/harness_runner.rs             | 20 +++++--------------
 kani-driver/src/metadata.rs                   | 14 ++++++++++---
 .../incomplete-harness-name/expected          |  2 +-
 .../some_matching_harnesses/expected          |  4 +---
 4 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/kani-driver/src/harness_runner.rs b/kani-driver/src/harness_runner.rs
index a5bd69e3390a..fdafa8a5c18b 100644
--- a/kani-driver/src/harness_runner.rs
+++ b/kani-driver/src/harness_runner.rs
@@ -177,22 +177,12 @@ impl KaniSession {
                         )
                     }
                     ([harness], None) => {
-                        if !self.args.exact {
-                            bail!("no harnesses matched the harness filter: `{harness}`")
-                        } else {
-                            bail!("no harnesses matched the name: `{harness}`")
-                        }
-                    }
-                    (harnesses, None) => {
-                        if !self.args.exact {
-                            bail!(
-                                "no harnesses matched the harness filters: `{}`",
-                                harnesses.join("`, `")
-                            )
-                        } else {
-                            bail!("no harnesses matched the names: `{}`", harnesses.join("`, `"))
-                        }
+                        bail!("no harnesses matched the harness filter: `{harness}`")
                     }
+                    (harnesses, None) => bail!(
+                        "no harnesses matched the harness filters: `{}`",
+                        harnesses.join("`, `")
+                    ),
                     ([], Some(func)) => error(&format!("No function named {func} was found")),
                     _ => unreachable!(
                         "invalid configuration. Cannot specify harness and function at the same time"
diff --git a/kani-driver/src/metadata.rs b/kani-driver/src/metadata.rs
index 8d9bc24ae226..bb855596b4aa 100644
--- a/kani-driver/src/metadata.rs
+++ b/kani-driver/src/metadata.rs
@@ -1,7 +1,7 @@
 // Copyright Kani Contributors
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 
-use anyhow::Result;
+use anyhow::{bail, Result};
 use std::path::{Path, PathBuf};
 use tracing::{debug, trace};
 
@@ -121,12 +121,20 @@ impl KaniSession {
             BTreeSet::from_iter(self.args.harnesses.iter())
         };
 
+        let total_harnesses = harnesses.len();
+
         if harnesses.is_empty() {
             Ok(Vec::from(all_harnesses))
         } else {
-            let harnesses: Vec<&HarnessMetadata> =
+            let harnesses_found: Vec<&HarnessMetadata> =
                 find_proof_harnesses(harnesses, all_harnesses, self.args.exact);
-            Ok(harnesses)
+            if self.args.exact && harnesses_found.len() < total_harnesses {
+                bail!(
+                    "Please provide exact harness name. One or more of the harnesses provided don't contain the full name.",
+                );
+            }
+
+            Ok(harnesses_found)
         }
     }
 }
diff --git a/tests/ui/exact-harness/incomplete-harness-name/expected b/tests/ui/exact-harness/incomplete-harness-name/expected
index b1cca2c68b25..c0c96ff536a5 100644
--- a/tests/ui/exact-harness/incomplete-harness-name/expected
+++ b/tests/ui/exact-harness/incomplete-harness-name/expected
@@ -1 +1 @@
-error: no harnesses matched the name: `check_blah`
+error: Please provide exact harness name. One or more of the harnesses provided don't contain the full name.
diff --git a/tests/ui/exact-harness/some_matching_harnesses/expected b/tests/ui/exact-harness/some_matching_harnesses/expected
index 45a411f32c0d..c0c96ff536a5 100644
--- a/tests/ui/exact-harness/some_matching_harnesses/expected
+++ b/tests/ui/exact-harness/some_matching_harnesses/expected
@@ -1,3 +1 @@
-Checking harness existing...
-VERIFICATION:- SUCCESSFUL
-Complete - 1 successfully verified harnesses, 0 failures, 1 total.
+error: Please provide exact harness name. One or more of the harnesses provided don't contain the full name.

From ad8529ac4f2af4a32522ed2be41ccc1dcfad605d Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Fri, 16 Jun 2023 22:37:10 +0000
Subject: [PATCH 6/9] add error on any missing harness with --exact

---
 kani-driver/src/metadata.rs                   | 21 ++++++++++++++++++-
 .../ui/exact-harness/fail_on_missing/expected |  1 +
 .../subset.rs                                 |  2 +-
 .../incomplete-harness-name/expected          |  2 +-
 .../incomplete_harness.rs                     |  2 +-
 .../some_matching_harnesses/expected          |  1 -
 6 files changed, 24 insertions(+), 5 deletions(-)
 create mode 100644 tests/ui/exact-harness/fail_on_missing/expected
 rename tests/ui/exact-harness/{some_matching_harnesses => fail_on_missing}/subset.rs (89%)
 delete mode 100644 tests/ui/exact-harness/some_matching_harnesses/expected

diff --git a/kani-driver/src/metadata.rs b/kani-driver/src/metadata.rs
index bb855596b4aa..a971c95e8ee8 100644
--- a/kani-driver/src/metadata.rs
+++ b/kani-driver/src/metadata.rs
@@ -122,15 +122,34 @@ impl KaniSession {
         };
 
         let total_harnesses = harnesses.len();
+        let all_targets = harnesses.clone();
 
         if harnesses.is_empty() {
             Ok(Vec::from(all_harnesses))
         } else {
             let harnesses_found: Vec<&HarnessMetadata> =
                 find_proof_harnesses(harnesses, all_harnesses, self.args.exact);
+
+            // If even one harness was not found with --exact, return an error to user
             if self.args.exact && harnesses_found.len() < total_harnesses {
+                let mut harness_found_names: BTreeSet<&String> = BTreeSet::new();
+
+                for harness in harnesses_found.clone() {
+                    harness_found_names.insert(&harness.pretty_name);
+                }
+
+                // Check which harnesses are missing from the difference of targets and harnesses_found
+                let harnesses_missing: Vec<&String> =
+                    all_targets.difference(&harness_found_names).cloned().collect();
+                let joined_string = harnesses_missing
+                    .iter()
+                    .map(|&s| (*s).clone())
+                    .collect::<Vec<String>>()
+                    .join("`, `");
+
                 bail!(
-                    "Please provide exact harness name. One or more of the harnesses provided don't contain the full name.",
+                    "Please provide exact harness name. The harnesses `{}` don't contain the full name.",
+                    joined_string
                 );
             }
 
diff --git a/tests/ui/exact-harness/fail_on_missing/expected b/tests/ui/exact-harness/fail_on_missing/expected
new file mode 100644
index 000000000000..f3d4920229cb
--- /dev/null
+++ b/tests/ui/exact-harness/fail_on_missing/expected
@@ -0,0 +1 @@
+error: Please provide exact harness name. The harnesses `check_blah`, `check_foo` don't contain the full name.
diff --git a/tests/ui/exact-harness/some_matching_harnesses/subset.rs b/tests/ui/exact-harness/fail_on_missing/subset.rs
similarity index 89%
rename from tests/ui/exact-harness/some_matching_harnesses/subset.rs
rename to tests/ui/exact-harness/fail_on_missing/subset.rs
index 02d14c39d1c7..943b2073ca30 100644
--- a/tests/ui/exact-harness/some_matching_harnesses/subset.rs
+++ b/tests/ui/exact-harness/fail_on_missing/subset.rs
@@ -1,6 +1,6 @@
 // Copyright Kani Contributors
 // SPDX-License-Identifier: Apache-2.0 OR MIT
-// kani-flags: --harness existing --harness check_blah --exact
+// kani-flags: --harness existing --harness check_blah --harness check_foo --exact
 //! Check that we just ignore non-matching filters
 
 mod first {
diff --git a/tests/ui/exact-harness/incomplete-harness-name/expected b/tests/ui/exact-harness/incomplete-harness-name/expected
index c0c96ff536a5..2f90b834ad9b 100644
--- a/tests/ui/exact-harness/incomplete-harness-name/expected
+++ b/tests/ui/exact-harness/incomplete-harness-name/expected
@@ -1 +1 @@
-error: Please provide exact harness name. One or more of the harnesses provided don't contain the full name.
+error: Please provide exact harness name. The harnesses `ignore_third_harness` don't contain the full name.
diff --git a/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs b/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
index d73137d1f04f..c2bc0e2a35ed 100644
--- a/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
+++ b/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
@@ -1,6 +1,6 @@
 // Copyright Kani Contributors
 // SPDX-License-Identifier: Apache-2.0 OR MIT
-// kani-flags: --harness check_blah --exact
+// kani-flags: --harness ignore_third_harness --exact
 //! Check that we just ignore non-matching filters
 
 mod first {
diff --git a/tests/ui/exact-harness/some_matching_harnesses/expected b/tests/ui/exact-harness/some_matching_harnesses/expected
deleted file mode 100644
index c0c96ff536a5..000000000000
--- a/tests/ui/exact-harness/some_matching_harnesses/expected
+++ /dev/null
@@ -1 +0,0 @@
-error: Please provide exact harness name. One or more of the harnesses provided don't contain the full name.

From 90ee54ee8814bcb4a3d5a228a631409c29b86b00 Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Mon, 19 Jun 2023 16:26:19 +0000
Subject: [PATCH 7/9] Address PR comments

---
 kani-driver/src/metadata.rs                   | 29 ++++++++-----------
 .../exact-harness/fail_on_missing/subset.rs   |  2 +-
 .../incomplete_harness.rs                     |  2 +-
 3 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/kani-driver/src/metadata.rs b/kani-driver/src/metadata.rs
index a971c95e8ee8..80bc3094d0ba 100644
--- a/kani-driver/src/metadata.rs
+++ b/kani-driver/src/metadata.rs
@@ -122,21 +122,17 @@ impl KaniSession {
         };
 
         let total_harnesses = harnesses.len();
-        let all_targets = harnesses.clone();
+        let all_targets = &harnesses;
 
         if harnesses.is_empty() {
             Ok(Vec::from(all_harnesses))
         } else {
             let harnesses_found: Vec<&HarnessMetadata> =
-                find_proof_harnesses(harnesses, all_harnesses, self.args.exact);
+                find_proof_harnesses(&harnesses, all_harnesses, self.args.exact);
 
             // If even one harness was not found with --exact, return an error to user
             if self.args.exact && harnesses_found.len() < total_harnesses {
-                let mut harness_found_names: BTreeSet<&String> = BTreeSet::new();
-
-                for harness in harnesses_found.clone() {
-                    harness_found_names.insert(&harness.pretty_name);
-                }
+                let harness_found_names: BTreeSet<&String> = harnesses_found.iter().map(|&h| &h.pretty_name).collect();
 
                 // Check which harnesses are missing from the difference of targets and harnesses_found
                 let harnesses_missing: Vec<&String> =
@@ -148,8 +144,7 @@ impl KaniSession {
                     .join("`, `");
 
                 bail!(
-                    "Please provide exact harness name. The harnesses `{}` don't contain the full name.",
-                    joined_string
+                    "Failed to match the following harness(es):\n{joined_string}\nPlease specify the fully-qualified name of a harness.",
                 );
             }
 
@@ -195,7 +190,7 @@ pub fn mock_proof_harness(
 /// At the present time, we use `no_mangle` so collisions shouldn't happen,
 /// but this function is written to be robust against that changing in the future.
 fn find_proof_harnesses<'a>(
-    targets: BTreeSet<&String>,
+    targets: &BTreeSet<&String>,
     all_harnesses: &[&'a HarnessMetadata],
     exact_filter: bool,
 ) -> Vec<&'a HarnessMetadata> {
@@ -241,7 +236,7 @@ mod tests {
         // Check with harness filtering
         assert_eq!(
             find_proof_harnesses(
-                BTreeSet::from([&"check_three".to_string()]),
+                &BTreeSet::from([&"check_three".to_string()]),
                 &ref_harnesses,
                 false
             )
@@ -249,14 +244,14 @@ mod tests {
             1
         );
         assert!(
-            find_proof_harnesses(BTreeSet::from([&"check_two".to_string()]), &ref_harnesses, false)
+            find_proof_harnesses(&BTreeSet::from([&"check_two".to_string()]), &ref_harnesses, false)
                 .first()
                 .unwrap()
                 .mangled_name
                 == "module::check_two"
         );
         assert!(
-            find_proof_harnesses(BTreeSet::from([&"check_one".to_string()]), &ref_harnesses, false)
+            find_proof_harnesses(&BTreeSet::from([&"check_one".to_string()]), &ref_harnesses, false)
                 .first()
                 .unwrap()
                 .mangled_name
@@ -277,18 +272,18 @@ mod tests {
 
         assert!(
             find_proof_harnesses(
-                BTreeSet::from([&"check_three".to_string()]),
+                &BTreeSet::from([&"check_three".to_string()]),
                 &ref_harnesses,
                 true
             )
             .is_empty()
         );
         assert!(
-            find_proof_harnesses(BTreeSet::from([&"check_two".to_string()]), &ref_harnesses, true)
+            find_proof_harnesses(&BTreeSet::from([&"check_two".to_string()]), &ref_harnesses, true)
                 .is_empty()
         );
         assert_eq!(
-            find_proof_harnesses(BTreeSet::from([&"check_one".to_string()]), &ref_harnesses, true)
+            find_proof_harnesses(&BTreeSet::from([&"check_one".to_string()]), &ref_harnesses, true)
                 .first()
                 .unwrap()
                 .mangled_name,
@@ -296,7 +291,7 @@ mod tests {
         );
         assert_eq!(
             find_proof_harnesses(
-                BTreeSet::from([&"module::not_check_three".to_string()]),
+                &BTreeSet::from([&"module::not_check_three".to_string()]),
                 &ref_harnesses,
                 true
             )
diff --git a/tests/ui/exact-harness/fail_on_missing/subset.rs b/tests/ui/exact-harness/fail_on_missing/subset.rs
index 943b2073ca30..6fe025dd44a3 100644
--- a/tests/ui/exact-harness/fail_on_missing/subset.rs
+++ b/tests/ui/exact-harness/fail_on_missing/subset.rs
@@ -1,7 +1,7 @@
 // Copyright Kani Contributors
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 // kani-flags: --harness existing --harness check_blah --harness check_foo --exact
-//! Check that we just ignore non-matching filters
+//! Check that we error out with non-matching filters when --exact is used
 
 mod first {
     #[kani::proof]
diff --git a/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs b/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
index c2bc0e2a35ed..0a1d6b44ed7f 100644
--- a/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
+++ b/tests/ui/exact-harness/incomplete-harness-name/incomplete_harness.rs
@@ -1,7 +1,7 @@
 // Copyright Kani Contributors
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 // kani-flags: --harness ignore_third_harness --exact
-//! Check that we just ignore non-matching filters
+//! Check that we error out with non-matching filters when --exact is used
 
 mod first {
     #[kani::proof]

From f03062f67d7e7df2630858f5c1817966d914da2c Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Mon, 19 Jun 2023 16:26:33 +0000
Subject: [PATCH 8/9] add formatting

---
 kani-driver/src/metadata.rs | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/kani-driver/src/metadata.rs b/kani-driver/src/metadata.rs
index 80bc3094d0ba..871be621c6b0 100644
--- a/kani-driver/src/metadata.rs
+++ b/kani-driver/src/metadata.rs
@@ -132,7 +132,8 @@ impl KaniSession {
 
             // If even one harness was not found with --exact, return an error to user
             if self.args.exact && harnesses_found.len() < total_harnesses {
-                let harness_found_names: BTreeSet<&String> = harnesses_found.iter().map(|&h| &h.pretty_name).collect();
+                let harness_found_names: BTreeSet<&String> =
+                    harnesses_found.iter().map(|&h| &h.pretty_name).collect();
 
                 // Check which harnesses are missing from the difference of targets and harnesses_found
                 let harnesses_missing: Vec<&String> =
@@ -244,17 +245,25 @@ mod tests {
             1
         );
         assert!(
-            find_proof_harnesses(&BTreeSet::from([&"check_two".to_string()]), &ref_harnesses, false)
-                .first()
-                .unwrap()
-                .mangled_name
+            find_proof_harnesses(
+                &BTreeSet::from([&"check_two".to_string()]),
+                &ref_harnesses,
+                false
+            )
+            .first()
+            .unwrap()
+            .mangled_name
                 == "module::check_two"
         );
         assert!(
-            find_proof_harnesses(&BTreeSet::from([&"check_one".to_string()]), &ref_harnesses, false)
-                .first()
-                .unwrap()
-                .mangled_name
+            find_proof_harnesses(
+                &BTreeSet::from([&"check_one".to_string()]),
+                &ref_harnesses,
+                false
+            )
+            .first()
+            .unwrap()
+            .mangled_name
                 == "check_one"
         );
     }

From 6b3febebcf04fca0ad06d42abfacba80d79e74a4 Mon Sep 17 00:00:00 2001
From: jaisnan <jaisnan@amazon.com>
Date: Mon, 19 Jun 2023 16:37:53 +0000
Subject: [PATCH 9/9] Fix expected files

---
 tests/ui/exact-harness/fail_on_missing/expected         | 4 +++-
 tests/ui/exact-harness/incomplete-harness-name/expected | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/tests/ui/exact-harness/fail_on_missing/expected b/tests/ui/exact-harness/fail_on_missing/expected
index f3d4920229cb..45cc61032413 100644
--- a/tests/ui/exact-harness/fail_on_missing/expected
+++ b/tests/ui/exact-harness/fail_on_missing/expected
@@ -1 +1,3 @@
-error: Please provide exact harness name. The harnesses `check_blah`, `check_foo` don't contain the full name.
+error: Failed to match the following harness(es):
+check_blah`, `check_foo
+Please specify the fully-qualified name of a harness.
diff --git a/tests/ui/exact-harness/incomplete-harness-name/expected b/tests/ui/exact-harness/incomplete-harness-name/expected
index 2f90b834ad9b..93ef322aeebb 100644
--- a/tests/ui/exact-harness/incomplete-harness-name/expected
+++ b/tests/ui/exact-harness/incomplete-harness-name/expected
@@ -1 +1,3 @@
-error: Please provide exact harness name. The harnesses `ignore_third_harness` don't contain the full name.
+error: Failed to match the following harness(es):
+ignore_third_harness
+Please specify the fully-qualified name of a harness.