travis " Segmentation fault " but works fine locally - travis-ci

Question

there, I ran into a 'Segmentation fault' error when using travis-ci for my project : IPython-Dashboard
there is no error msg and it works fine on local, I feel a little confusing. any one can give any idea on fixing this, thanks.
here is the travis build log on cloud:
travis-log
$ nosetests --with-coverage --cover-package=dashboard
../home/travis/build.sh: line 45: 3187 Segmentation fault (core dumped)
nosetests --with-coverage --cover-package=dashboard
The command "nosetests --with-coverage --cover-package=dashboard" exited with 139.
here is the build log on local [osx]
taotao#mac007:~/Desktop/github/IPython-Dashboard$sudo nosetests --with-coverage --cover-package=dashboard
.../Users/chenshan/Desktop/github/IPython-Dashboard/dashboard/tests/testCreateData.py:78: Warning: Can't create database 'IPD_data'; database exists
conn.cursor().execute('CREATE DATABASE IF NOT EXISTS {};'.format(config.sql_db))
/Library/Python/2.7/site-packages/pandas/io/sql.py:599: FutureWarning: The 'mysql' flavor with DBAPI connection is deprecated and will be removed in future versions. MySQL will be further supported with SQLAlchemy engines.
warnings.warn(_MYSQL_WARNING, FutureWarning)
...
Name Stmts Miss Cover Missing
---------------------------------------------------------------------
dashboard.py 13 0 100%
dashboard/client.py 1 0 100%
dashboard/client/sender.py 11 3 73% 26-27, 33
dashboard/conf.py 0 0 100%
dashboard/conf/config.py 29 0 100%
dashboard/server.py 0 0 100%
dashboard/server/resources.py 0 0 100%
dashboard/server/resources/dash.py 35 10 71% 36, 55-56, 67-69, 86-89
dashboard/server/resources/home.py 40 12 70% 25, 28-30, 83-91
dashboard/server/resources/sql.py 27 11 59% 30, 52-75
dashboard/server/resources/status.py 8 1 88% 19
dashboard/server/resources/storage.py 13 5 62% 26-28, 43-47
dashboard/server/utils.py 79 18 77% 20-24, 78-80, 82-83, 86, 96, 99-100, 126-127, 140-142
dashboard/server/views.py 21 1 95% 16
---------------------------------------------------------------------
TOTAL 277 61 78%
----------------------------------------------------------------------
Ran 6 tests in 4.600s
OK
taotao#mac007:~/Desktop/github/IPython-Dashboard$