[C++] unittest failure for language environment

[asfimport]

After clone the project and run "make unittest" ,the "io-file-test" has error:

locale::facet::_S_create_c_locale name not valid

need to add LC_ALL="en_US.UTF-8" to pass this test

Environment: ubuntu14.04 gcc4.8.4
Reporter: Lu Qi / @luchy0120
Assignee: Wes McKinney / @wesm

PRs and other links:

• GitHub Pull Request #1284

_{Note: This issue was originally created as ARROW-1762. Please see the migration documentation for further details.}

[asfimport]

Uwe Korn / @xhochy:
See the SO answer to this problem: https://stackoverflow.com/a/19905162/1689261 This is probably due to missing locales on the system. I'm not sure if we can do anything here, this might be a requirement of the external functions we're calling.

[asfimport]

Uwe Korn / @xhochy:
Issue resolved by pull request 1284
#1284