From 5819536f00ace91660c95ef7d65ff1c425a7b5b8 Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Fri, 28 Feb 2020 19:41:56 +0100
Subject: [PATCH] Improve UsageError with invalid `-o` style (#6795)

This started from fixing the test, where `"xdist_strict True"` was used
as a single argument, although you typically would see `["xdist_strict",
"True"]`.

Improves the error message to mention the option that caused the error.
---
 changelog/6795.improvement.rst | 1 +
 src/_pytest/config/__init__.py | 6 +++++-
 testing/test_config.py         | 8 ++++++--
 3 files changed, 12 insertions(+), 3 deletions(-)
 create mode 100644 changelog/6795.improvement.rst

diff --git a/changelog/6795.improvement.rst b/changelog/6795.improvement.rst
new file mode 100644
index 000000000..b1fd70d8a
--- /dev/null
+++ b/changelog/6795.improvement.rst
@@ -0,0 +1 @@
+Import usage error message with invalid `-o` option.
diff --git a/src/_pytest/config/__init__.py b/src/_pytest/config/__init__.py
index b8e0bad99..3107950f6 100644
--- a/src/_pytest/config/__init__.py
+++ b/src/_pytest/config/__init__.py
@@ -1131,7 +1131,11 @@ class Config:
             try:
                 key, user_ini_value = ini_config.split("=", 1)
             except ValueError:
-                raise UsageError("-o/--override-ini expects option=value style.")
+                raise UsageError(
+                    "-o/--override-ini expects option=value style (got: {!r}).".format(
+                        ini_config
+                    )
+                )
             else:
                 if key == name:
                     value = user_ini_value
diff --git a/testing/test_config.py b/testing/test_config.py
index c446a4141..be728c0fc 100644
--- a/testing/test_config.py
+++ b/testing/test_config.py
@@ -1089,8 +1089,12 @@ class TestOverrideIniArgs:
             xdist_strict=False
         """
         )
-        result = testdir.runpytest("--override-ini", "xdist_strict True", "-s")
-        result.stderr.fnmatch_lines(["*ERROR* *expects option=value*"])
+        result = testdir.runpytest("--override-ini", "xdist_strict", "True")
+        result.stderr.fnmatch_lines(
+            [
+                "ERROR: -o/--override-ini expects option=value style (got: 'xdist_strict').",
+            ]
+        )
 
     @pytest.mark.parametrize("with_ini", [True, False])
     def test_override_ini_handled_asap(self, testdir, with_ini):