docs: kdoc: handle the obsolescensce of docutils.ErrorString()

The ErrorString() and SafeString() docutils functions were helpers meant to
ease the handling of encodings during the Python 3 transition.  There is no
real need for them after Python 3.6, and docutils 0.22 removes them,
breaking the docs build

Handle this by just injecting our own one-liner version of ErrorString(),
and removing the sole SafeString() call entirely.

Reported-by: Zhixu Liu <zhixu.liu@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <87ldmnv2pi.fsf@trenco.lwn.net>

3 files changed, 10 insertions, 4 deletions

diff --git a/Documentation/sphinx/kernel_feat.py b/Documentation/sphinx/kernel_feat.py
index e3a51867f27b..aaac76892ceb 100644
--- a/Documentation/sphinx/kernel_feat.py
+++ b/Documentation/sphinx/kernel_feat.py
@@ -40,9 +40,11 @@ import sys
 from docutils import nodes, statemachine
 from docutils.statemachine import ViewList
 from docutils.parsers.rst import directives, Directive
-from docutils.utils.error_reporting import ErrorString
 from sphinx.util.docutils import switch_source_input
 
+def ErrorString(exc):  # Shamelessly stolen from docutils
+    return f'{exc.__class__.__name}: {exc}'
+
 __version__  = '1.0'
 
 def setup(app):
diff --git a/Documentation/sphinx/kernel_include.py b/Documentation/sphinx/kernel_include.py
index 2c4bb8215b4c..f94412cd17c9 100755
--- a/Documentation/sphinx/kernel_include.py
+++ b/Documentation/sphinx/kernel_include.py
@@ -89,7 +89,6 @@ import sys
 
 from docutils import io, nodes, statemachine
 from docutils.statemachine import ViewList
-from docutils.utils.error_reporting import SafeString, ErrorString
 from docutils.parsers.rst import Directive, directives
 from docutils.parsers.rst.directives.body import CodeBlock, NumberLines
 
@@ -106,6 +105,9 @@ logger = logging.getLogger(__name__)
 RE_DOMAIN_REF = re.compile(r'\\ :(ref|c:type|c:func):`([^<`]+)(?:<([^>]+)>)?`\\')
 RE_SIMPLE_REF = re.compile(r'`([^`]+)`')
 
+def ErrorString(exc):  # Shamelessly stolen from docutils
+    return f'{exc.__class__.__name}: {exc}'
+
 
 # ==============================================================================
 class KernelInclude(Directive):
@@ -156,7 +158,7 @@ class KernelInclude(Directive):
             except UnicodeEncodeError:
                 raise self.severe('Problems with directive path:\n'
                                 'Cannot encode input file path "%s" '
-                                '(wrong locale?).' % SafeString(path))
+                                '(wrong locale?).' % path)
             except IOError as error:
                 raise self.severe('Problems with directive path:\n%s.' % ErrorString(error))
 
diff --git a/Documentation/sphinx/maintainers_include.py b/Documentation/sphinx/maintainers_include.py
index d31cff867436..519ad18685b2 100755
--- a/Documentation/sphinx/maintainers_include.py
+++ b/Documentation/sphinx/maintainers_include.py
@@ -22,10 +22,12 @@ import re
 import os.path
 
 from docutils import statemachine
-from docutils.utils.error_reporting import ErrorString
 from docutils.parsers.rst import Directive
 from docutils.parsers.rst.directives.misc import Include
 
+def ErrorString(exc):  # Shamelessly stolen from docutils
+    return f'{exc.__class__.__name}: {exc}'
+
 __version__  = '1.0'
 
 def setup(app):