我正在运行的命令：
alembic -c development.ini revision --autogenerate -m "test"
我得到以下结果：
Traceback (most recent call last):
File "/Users/charleswesley/.virtualenvs/foundation/bin/alembic", line 9, in <module>
load_entry_point('alembic==0.6.1', 'console_scripts', 'alembic')()
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/config.py", line 298, in main
CommandLine(prog=prog).main(argv=argv)
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/config.py", line 293, in main
self.run_cmd(cfg, options)
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/config.py", line 279, in run_cmd
**dict((k, getattr(options, k)) for k in kwarg)
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/command.py", line 97, in revision
script.run_env()
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/script.py", line 199, in run_env
util.load_python_file(self.dir, 'env.py')
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/util.py", line 198, in load_python_file
module = load_module(module_id, path)
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/compat.py", line 49, in load_module
return machinery.SourceFileLoader(module_id, path).load_module()
File "<frozen importlib._bootstrap>", line 586, in _check_name_wrapper
File "<frozen importlib._bootstrap>", line 1024, in load_module
File "<frozen importlib._bootstrap>", line 1005, in load_module
File "<frozen importlib._bootstrap>", line 562, in module_for_loader_wrapper
File "<frozen importlib._bootstrap>", line 870, in _load_module
File "<frozen importlib._bootstrap>", line 313, in _call_with_frames_removed
File "/Users/charleswesley/repos/foundation/foundation/scripts/alembic/env.py", line 74, in <module>
run_migrations_online()
File "/Users/charleswesley/repos/foundation/foundation/scripts/alembic/env.py", line 67, in run_migrations_online
context.run_migrations()
File "<string>", line 7, in run_migrations
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/environment.py", line 652, in run_migrations
self.get_context().run_migrations(**kw)
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/migration.py", line 210, in run_migrations
self):
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/command.py", line 83, in retrieve_migrations
autogen._produce_migration_diffs(context, template_args, imports)
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/autogenerate/api.py", line 143, in _produce_migration_diffs
autogen_context, object_filters, include_schemas)
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/autogenerate/api.py", line 198, in _produce_net_changes
inspector, metadata, diffs, autogen_context)
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/autogenerate/compare.py", line 32, in _compare_tables
set())
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/autogenerate/compare.py", line 243, in _compare_indexes
for i in reflected_indexes
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/autogenerate/compare.py", line 243, in <genexpr>
for i in reflected_indexes
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/autogenerate/compare.py", line 83, in _make_index
unique=params['unique']
File "/Users/charleswesley/.virtualenvs/foundation/lib/python3.3/site-packages/alembic-0.6.1-py3.3.egg/alembic/autogenerate/compare.py", line 82, in <listcomp>
*[conn_table.c[cname] for cname in params['column_names']],
AttributeError: 'NoneType' object has no attribute 'c'
我真的不确定这里会出现什么问题。我正在尝试使用Postgres 9.2，SQLAlchemy 0.8.4和Alembic 0.6.1。但我在Postgres 9.3，SQLAlchemy 0.9和Alembic 0.6.2中看到了相同的结果。我们正在使用自定义数据库模式，如果这有所不同。