Issue #19543: Emit deprecation warning for known non-text encodings.
Backported issues #19619: encode() and decode() methods and constructors
of str, unicode and bytearray classes now emit deprecation warning for known
non-text encodings when Python is ran with the -3 option.
Backported issues #20404: io.TextIOWrapper (and hence io.open()) now uses the
internal codec marking system added to emit deprecation warning for known non-text
encodings at stream construction time when Python is ran with the -3 option.
diff --git a/Lib/encodings/hex_codec.py b/Lib/encodings/hex_codec.py
index 91b38d9..154488c 100644
--- a/Lib/encodings/hex_codec.py
+++ b/Lib/encodings/hex_codec.py
@@ -76,4 +76,5 @@
incrementaldecoder=IncrementalDecoder,
streamwriter=StreamWriter,
streamreader=StreamReader,
+ _is_text_encoding=False,
)