Failing test cases on travis due to IOinput exception

[PhiLong-Ho]

I try to use FileOutPutStream to write to a file, and it seems to work on my local machine. However, the test cases which I passed on my machine seem to fail on travis and I have not figured out what is wrong? I only know the cause is IOinput exception but doesn't know the cause for that, as it work normally on local machine.
Can anyone give me a hint for this.

[yamgent]

You can ask Travis to be more verbose in the logging, might reveal more information about the error. See here for more information.