[pypy-issue] Issue #2746: Flask not working on windows (pypy/pypy)

[Luigi Bardelli]

New issue 2746: Flask not working on windows
https://bitbucket.org/pypy/pypy/issues/2746/flask-not-working-on-windows

Luigi Bardelli:

Hi, 
   newbie here :| After developing some code on Linux I am trying moving it to windows, and I get an error with Flask. 
I am using windows10 64bit, pypy3-v5.10.1-win32 , with pip installed via get-pip.py , and a standard pip install flask.
On the same machine, the same code works fine on python 3.6.4 32bit.

I have reduced the file to the minimal sample in attachment. The error I get is:


```
#!text

Traceback (most recent call last):
  File "test_flask2.py", line 1, in <module>
    from flask import Flask
<my path>\pypy3-v5.10.1-win32\site-packages\flask\__init__.py", line 19, in <module>
    from jinja2 import Markup, escape
<my path>\pypy3-v5.10.1-win32\site-packages\jinja2\__init__.py", line 33, in <module>
    from jinja2.environment import Environment, Template
<my path>\pypy3-v5.10.1-win32\site-packages\jinja2\environment.py", line 22, in <module>
    from jinja2.lexer import get_lexer, TokenStream
<my path>\pypy3-v5.10.1-win32\site-packages\jinja2\lexer.py", line 46, in <module>
    name_re = re.compile(r'[\w{0}]+'.format(_identifier.pattern))
<my path>\pypy3-v5.10.1-win32\lib-python\3\re.py", line 224, in compile
    return _compile(pattern, flags)
<my path>\pypy3-v5.10.1-win32\lib-python\3\re.py", line 293, in _compile
    p = sre_compile.compile(pattern, flags)
<my path>\pypy3-v5.10.1-win32\lib-python\3\sre_compile.py", line 540, in compile
    p = sre_parse.parse(p, flags)
<my path>\pypy3-v5.10.1-win32\lib-python\3\sre_parse.py", line 829, in parse
    p = _parse_sub(source, pattern, 0)
<my path>\pypy3-v5.10.1-win32\lib-python\3\sre_parse.py", line 437, in _parse_sub
    itemsappend(_parse(source, state))
<my path>\pypy3-v5.10.1-win32\lib-python\3\sre_parse.py", line 575, in _parse
    raise source.error(msg, len(this) + 1 + len(that))
sre_constants.error: bad character range \udf76-\ud800 at position 459

```

Do you have any idea? Thanks!