Too many open files

[euphoris]

earthreader-web raises a following error:

(earthweb1)jmair:earthweb jae-myoungyu$ earthreader server --debug ~/Dropbox/rss
Traceback (most recent call last):
File "/Users/jae-myoungyu/ENV/earthweb1/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
File "/Users/jae-myoungyu/repo/earthreader/earthweb/earthreader/web/wsgi.py", line 59, in __call__
File "/Users/jae-myoungyu/ENV/earthweb1/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
File "/Users/jae-myoungyu/ENV/earthweb1/lib/python2.7/site-packages/flask/app.py", line 1403, in handle_exception
File "/Users/jae-myoungyu/ENV/earthweb1/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
File "/Users/jae-myoungyu/ENV/earthweb1/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
File "/Users/jae-myoungyu/ENV/earthweb1/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
File "/Users/jae-myoungyu/ENV/earthweb1/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
File "/Users/jae-myoungyu/ENV/earthweb1/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
File "/Users/jae-myoungyu/repo/earthreader/earthweb/earthreader/web/app.py", line 689, in category_entries
File "/Users/jae-myoungyu/repo/earthreader/libearth-0.1/libearth/stage.py", line 729, in __getitem__
File "/Users/jae-myoungyu/repo/earthreader/libearth-0.1/libearth/stage.py", line 273, in read_merged_document
File "/Users/jae-myoungyu/repo/earthreader/libearth-0.1/libearth/stage.py", line 252, in read
File "/Users/jae-myoungyu/repo/earthreader/libearth-0.1/libearth/stage.py", line 213, in touch
File "/Users/jae-myoungyu/repo/earthreader/libearth-0.1/libearth/repository.py", line 368, in write
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/tempfile.py", line 447, in NamedTemporaryFile
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/tempfile.py", line 228, in _mkstemp_inner
OSError: [Errno 24] Too many open files: '/var/folders/4d/g1kv9vx169n6k_yf255zfhr40000gn/T/tmpyPQfsJ'