Fix SyntaxError on python 2.7.5

[asottile]

Resolves #1544

Here's the test plan I used, since we can't install 2.7.5 in CI this'll have to do:

$ docker run --rm -ti -v "$PWD:/code:ro" centos:7
...
[root@9b75ddb7a51a code]# python -m compileall src/werkzeug/routing.py 
Compiling src/werkzeug/routing.py ...
SyntaxError: unqualified exec is not allowed in function '_compile_builder' it contains a nested function with free variables (routing.py, line 948)

    # outside of docker, I did `git apply patch` to get to the code you see in this PR

[root@9b75ddb7a51a code]# python -m compileall src/werkzeug/routing.py 
Compiling src/werkzeug/routing.py ...
Sorry [Errno 30] Read-only file system: 'src/werkzeug/routing.pyc'

[davidism]

Would you retarget to 0.15.x?

Also, this seems to break the tests.

tests/test_routing.py:29: in test_basic_routing
    r.Rule("/bar/", endpoint="bar"),
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:1347: in __init__
    self.add(rulefactory)
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:1388: in add
    rule.bind(self)
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:730: in bind
    self.compile()
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:794: in compile
    self._build = self._compile_builder(False).__get__(self, None)
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:952: in _compile_builder
    return self._get_func_code(code, func_ast.name)
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:859: in _get_func_code
    return locs[name]
E   KeyError: "<builder:'/'>"

[asottile]

Would you retarget to 0.15.x?

Also, this seems to break the tests.

tests/test_routing.py:29: in test_basic_routing
    r.Rule("/bar/", endpoint="bar"),
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:1347: in __init__
    self.add(rulefactory)
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:1388: in add
    rule.bind(self)
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:730: in bind
    self.compile()
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:794: in compile
    self._build = self._compile_builder(False).__get__(self, None)
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:952: in _compile_builder
    return self._get_func_code(code, func_ast.name)
.tox/py/lib/python3.7/site-packages/werkzeug/routing.py:859: in _get_func_code
    return locs[name]
E   KeyError: "<builder:'/'>"

lol oops, transposed globs and locs while copying the code 🤦‍♂

[davidism]

I was trying to spot the difference 😆

[davidism]

You'll need to git rebase --onto origin/0.15.x master, changing the base here isn't enough.

[asottile]

fixed my rebase too -- oops, I'm sick and not thinking super straight

[davidism]

Thanks for the quick fix!

[asottile]

No problem! Ya learn some archaic fact every day I guess 😆