Hi Werner:

In message <1615387874.91.0.944369845492.issue2551115@roundup.psfhosted.org>,
Werner Hunger writes:
>I just stumbled over the upgrading instructions to 2.x for MySQL
>users
>(https://www.roundup-tracker.org/docs/upgrading.html#python-2-mysql-users-must-read),

Have you successfully upgraded? Those docs were written with minimal if
any testing. Nobody on the core team runs mysql. Any feedback on those
docs would be appreciated.

>to which i would like to propose an improvement.
>
>I would not advise to set the MySQL database encoding to utf, but to
>utf8mb4 instead. Utf8 in MySQL is limited to use only up to 3 bytes
>per character, and thus cannot store all characters that you would
>expect maybe. Especially Emojis will not work, which is a pity, as
>these have a high probability of arriving through the Email interface

This makes sense. Nobody on the primary team runs mysql so we weren't
up on the nuances. I have updated the docs and changed the config
variable to use utf8mb4. The diffs are below:

diff -r 6a6b4651be1f doc/upgrading.txt
--- a/doc/upgrading.txt Thu Mar 04 12:55:21 2021 +0100
+++ b/doc/upgrading.txt Wed Mar 10 10:30:03 2021 -0500
@@ -77,10 +77,10 @@
 python3. See `Python 3 support`_.

 In an upgraded ``config.ini`` (see next section) the ``[rdbms]``
-section has a key ``mysql_charset`` set by default to ``utf-8``.
-
-It should be possible to change utf-8 to any mysql charset. So if you
-know what charset is enabled (e.g. via a setting in ~roundup/.my.cnf,
+section has a key ``mysql_charset`` set by default to ``utf8mb4``.
+
+It should be possible to change ``utf8mb4`` to any mysql charset. So
+if you know what charset is enabled (e.g. via a setting in ~roundup/.my.cnf,
 or the default charset for the database) you can set it in
 ``config.ini`` and not need to covert the database. However the
 underlying issues with misconverted data and bad searches will still
diff -r 6a6b4651be1f roundup/configuration.py
--- a/roundup/configuration.py  Thu Mar 04 12:55:21 2021 +0100
+++ b/roundup/configuration.py  Wed Mar 10 10:30:03 2021 -0500
@@ -1048,7 +1048,7 @@
         (NullableOption, 'read_default_group', 'roundup',
             "Name of the group to use in the MySQL defaults file (.my.cnf).\n"
             "Only used in MySQL connections."),
-        (Option, 'mysql_charset', 'utf8',
+        (Option, 'mysql_charset', 'utf8mb4',
             "Charset to use for mysql connection,\n"
             "use 'default' for the mysql default, no charset option\n"
             "is used when creating the connection in that case.\n"

committed in rev bd84f43e1d13.

Does this fix your request?