Python 3.8 test error: AttributeError: 'Constant' object has no attribute 'n'

[hroncok]

This is Python 3.8.0a3. I had to modify the tox.ini to have basepython set for 3.8:

diff --git a/tox.ini b/tox.ini
index c81ac77..f40958d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    py27,py33,py34,py35,py36,py37,pypy,
+    py27,py33,py34,py35,py36,py37,py38,pypy,
     docs,{py2,py3}-cover,coverage
 skip_missing_interpreters = True
 
@@ -14,6 +14,7 @@ basepython =
     py35: python3.5
     py36: python3.6
     py37: python3.7
+    py38: python3.8
     pypy: pypy
     py2: python2.7
     py3: python3.5

And when i run tox for 3.8 on master (333986c):

$ tox -e py38
GLOB sdist-make: .../pyramid_mako/setup.py
py38 inst-nodeps: .../pyramid_mako/.tox/.tmp/package/1/pyramid_mako-1.0.3.dev0.zip
py38 installed: beautifulsoup4==4.7.1,coverage==4.5.3,hupper==1.6.1,Mako==1.0.8,MarkupSafe==1.1.1,nose==1.3.7,PasteDeploy==2.0.1,plaster==1.0,plaster-pastedeploy==0.6,pyramid==1.10.2,pyramid-mako==1.0.3.dev0,six==1.12.0,soupsieve==1.9,translationstring==1.3,venusian==1.2.0,waitress==1.2.1,WebOb==1.8.5,WebTest==2.0.33,zope.deprecation==4.4.0,zope.interface==4.6.0
py38 run-test-pre: PYTHONHASHSEED='1721400932'
py38 runtests: commands[0] | pip install 'pyramid_mako[testing]'
Requirement already satisfied: pyramid_mako[testing] in ./.tox/py38/lib/python3.8/site-packages (1.0.3.dev0)
Requirement already satisfied: Mako>=0.8 in ./.tox/py38/lib/python3.8/site-packages (from pyramid_mako[testing]) (1.0.8)
Requirement already satisfied: pyramid in ./.tox/py38/lib/python3.8/site-packages (from pyramid_mako[testing]) (1.10.2)
Requirement already satisfied: nose; extra == "testing" in ./.tox/py38/lib/python3.8/site-packages (from pyramid_mako[testing]) (1.3.7)
Requirement already satisfied: WebTest>=1.3.1; extra == "testing" in ./.tox/py38/lib/python3.8/site-packages (from pyramid_mako[testing]) (2.0.33)
Requirement already satisfied: coverage; extra == "testing" in ./.tox/py38/lib/python3.8/site-packages (from pyramid_mako[testing]) (4.5.3)
Requirement already satisfied: MarkupSafe>=0.9.2 in ./.tox/py38/lib/python3.8/site-packages (from Mako>=0.8->pyramid_mako[testing]) (1.1.1)
Requirement already satisfied: zope.interface>=3.8.0 in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (4.6.0)
Requirement already satisfied: plaster in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (1.0)
Requirement already satisfied: plaster-pastedeploy in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (0.6)
Requirement already satisfied: zope.deprecation>=3.5.0 in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (4.4.0)
Requirement already satisfied: translationstring>=0.4 in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (1.3)
Requirement already satisfied: venusian>=1.0 in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (1.2.0)
Requirement already satisfied: hupper in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (1.6.1)
Requirement already satisfied: webob>=1.8.3 in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (1.8.5)
Requirement already satisfied: setuptools in ./.tox/py38/lib/python3.8/site-packages (from pyramid->pyramid_mako[testing]) (41.0.0)
Requirement already satisfied: beautifulsoup4 in ./.tox/py38/lib/python3.8/site-packages (from WebTest>=1.3.1; extra == "testing"->pyramid_mako[testing]) (4.7.1)
Requirement already satisfied: six in ./.tox/py38/lib/python3.8/site-packages (from WebTest>=1.3.1; extra == "testing"->pyramid_mako[testing]) (1.12.0)
Requirement already satisfied: waitress>=0.8.5 in ./.tox/py38/lib/python3.8/site-packages (from WebTest>=1.3.1; extra == "testing"->pyramid_mako[testing]) (1.2.1)
Requirement already satisfied: PasteDeploy>=1.5.0 in ./.tox/py38/lib/python3.8/site-packages (from plaster-pastedeploy->pyramid->pyramid_mako[testing]) (2.0.1)
Requirement already satisfied: soupsieve>=1.2 in ./.tox/py38/lib/python3.8/site-packages (from beautifulsoup4->WebTest>=1.3.1; extra == "testing"->pyramid_mako[testing]) (1.9)
py38 runtests: commands[1] | nosetests --with-xunit --xunit-file=nosetests-py38.xml
.E..............................................................................
======================================================================
ERROR: test_call_render_raises (pyramid_mako.tests.MakoLookupTemplateRendererTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File ".../pyramid_mako/pyramid_mako/__init__.py", line 148, in __call__
    result = template.render_unicode(**system)
  File ".../pyramid_mako/pyramid_mako/tests.py", line 665, in render_unicode
    raise self.render_exc
NotImplementedError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File ".../pyramid_mako/pyramid_mako/tests.py", line 364, in test_call_render_raises
    instance({}, {})
  File ".../pyramid_mako/pyramid_mako/__init__.py", line 152, in __call__
    errtext = text_error_template().render(
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/exceptions.py", line 236, in text_error_template
    return mako.template.Template(r"""
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/template.py", line 320, in __init__
    (code, module) = _compile_text(self, text, filename)
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/template.py", line 704, in _compile_text
    source, lexer = _compile(template, text, filename,
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/template.py", line 686, in _compile
    source = codegen.compile(node,
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/codegen.py", line 52, in compile
    _GenerateRenderMethod(printer,
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/codegen.py", line 127, in __init__
    args = pagetag.body_decl.get_argument_expressions()
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/ast.py", line 175, in get_argument_expressions
    name, pyparser.ExpressionGenerator(default).value()))
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/pyparser.py", line 230, in __init__
    self.generator.visit(astnode)
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/_ast_util.py", line 279, in visit
    return f(node)
  File ".../pyramid_mako/.tox/py38/lib/python3.8/site-packages/mako/_ast_util.py", line 685, in visit_Constant
    self.write(repr(node.n))
AttributeError: 'Constant' object has no attribute 'n'

----------------------------------------------------------------------
Ran 80 tests in 0.367s

FAILED (errors=1)
ERROR: InvocationError for command '.../pyramid_mako/.tox/py38/bin/nosetests --with-xunit --xunit-file=nosetests-py38.xml' (exited with code 1)
___________________________________ summary ____________________________________
ERROR:   py38: commands failed

[stevepiercy]

The bug mentioned in sqlalchemy/mako#287 got released in mako 1.0.8.

If you have a fix for pyramid_mako, please submit a PR.

See also the open issue #44 and PR #46.

[hroncok]

I think I know what the problem is (in mako).

EDIT: See sqlalchemy/mako#287 (comment)

[hroncok]

sqlalchemy/mako#292