From 866406bf87a583f911b2a490ad784239c5c17d5f Mon Sep 17 00:00:00 2001
From: Alexander Held <45009355+alexander-held@users.noreply.github.com>
Date: Thu, 27 Feb 2025 23:35:08 +0100
Subject: [PATCH] feat: improve error message when CLs bracketing fails (#509)

* add POI name to error message to better distinguish between POI and CLs values
---
 src/cabinetry/fit/__init__.py | 5 +++--
 tests/fit/test_fit.py         | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/cabinetry/fit/__init__.py b/src/cabinetry/fit/__init__.py
index 499bd6e9..ed894436 100644
--- a/src/cabinetry/fit/__init__.py
+++ b/src/cabinetry/fit/__init__.py
@@ -995,8 +995,9 @@ def _cls_minus_threshold(
         except ValueError:
             # invalid starting bracket is most common issue
             log.error(
-                f"CLs values at {bracket[0]:.4f} and {bracket[1]:.4f} do not bracket "
-                f"CLs={cls_target:.4f}, try a different starting bracket"
+                f"CLs values for {model.config.poi_name}={bracket[0]:.4f} and "
+                f"{bracket[1]:.4f} do not bracket CLs={cls_target:.4f}, try a "
+                "different starting bracket"
             )
             # set POI in model back to original value
             model.config.set_poi(original_model_poi_name)
diff --git a/tests/fit/test_fit.py b/tests/fit/test_fit.py
index 93bb6e89..715fbf37 100644
--- a/tests/fit/test_fit.py
+++ b/tests/fit/test_fit.py
@@ -818,8 +818,8 @@ def test_limit(example_spec_with_background, caplog):
             poi_name="Signal strength",
         )
     assert (
-        "CLs values at 1.0000 and 2.0000 do not bracket CLs=0.1000, try a different "
-        "starting bracket" in [rec.message for rec in caplog.records]
+        "CLs values for Signal strength=1.0000 and 2.0000 do not bracket CLs=0.1000, "
+        "try a different starting bracket" in [rec.message for rec in caplog.records]
     )
     caplog.clear()