--- product/ERP5/bootstrap/erp5_core/ToolTemplateItem/mimetypes_registry.xml
+++ product/ERP5/bootstrap/erp5_core/ToolTemplateItem/mimetypes_registry.xml
@@ -73530,7 +73530,7 @@
                 <global id="1207.1" name="_compile" module="re"/>
               </klass>
               <tuple>
-                <unicode>.*\\%\\Z(?ms)</unicode>
+                <unicode>(?ms).*\\%\\Z</unicode>
                 <int>24</int>
               </tuple>
             </object>

@jerome this comes from the code in MimetypesRegistry.py

    def register_glob(self, glob, mimetype):
...
        pattern = re.compile(fnmatch.translate(glob))

In py2:

>>> fnmatch.translate('*.aaa')
'.*\\.aaa\\Z(?ms)'

In py3:

>>> fnmatch.translate('*.aaa')
'(?s:.*\\.aaa)\\Z'

and boths are incompatible in the other...

py3 result in py2

>>> re.compile('(?s:.*\\.aaa)\\Z')
...
error: unknown extension

py2 result in py3

>>> re.compile('.*\\.aaa\\Z(?ms)')
...
re.error: global flags not at the start of the expression at position 9

What can we do to prevent this kind of commit again and again ?

Thanks for investigating. I don't see a solution for this. This does not look extremely bad, because for now, we can manually edit the .xml like I did after we update mimetypes and we don't update mimetypes too often.

I suggest we push this commit in master, with your explanation about where it comes from and also an explanation about how I made this commit.