Open log file with utf-8 encoding.

Updated pycln version due to this issue: https://github.com/hadialqattan/pycln/issues/249

.pre-commit-config.yaml

@@ -28,7 +28,7 @@ repos:
     hooks:
       - id: black
   - repo: https://github.com/hadialqattan/pycln  # removes unused imports
-    rev: v2.3.0
+    rev: v2.5.0
     hooks:
       - id: pycln
         language_version: '3.11'

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+### Fixed
+
+- Fixed logging to a file on Windows https://github.com/Textualize/textual/issues/5941
+
 ## [3.7.1] - 2025-07-09
 
 ### Fixed

src/textual/__init__.py

@@ -90,7 +90,7 @@ class Logger:
                 )
                 output = f"{output} {key_values}" if output else key_values
 
-            with open(constants.LOG_FILE, "a") as log_file:
+            with open(constants.LOG_FILE, "a", encoding="utf-8") as log_file:
                 print(output, file=log_file)
 
         app = self.app