Certain snapd tests don't take into account system locale differences

[Arseniy Aharonov]

The following tests fail if the host Linux is configured to certain locales (e.g. en_GB):

  - cmd_list_test.go:31: SnapSuite.TestListHelp
  - cmd_login_test.go:70: SnapSuite.TestLoginAskEmail
  - cmd_reboot_test.go:33: SnapSuite.TestRebootHelp
  - cmd_recovery_test.go:32: SnapSuite.TestRecoveryHelp
  - cmd_snapshot_test.go:79: SnapSuite.TestSnapSnaphotsTest
  - cmd_whoami_test.go:31: SnapSuite.TestWhoamiLoggedInUser
  - cmd_whoami_test.go:44: SnapSuite.TestWhoamiNotLoggedInUser

These tests capture STDOUT and compare the results to the expected strings. The tests assume that in all locales the captured output looks the same, which is not. That is why for most locales it will pass, but for some it will fail.

Current workaround is to set an environment variable `LANG` to value `C.UTF-8`. This sets a locale for which the aforementioned tests won't fail.

[Arseniy Aharonov (arsenique)]

Once this issue gets fixed the HACKING.md of snapd repo should be updated (see https://github.com/snapcore/snapd/blob/master/HACKING.md). It's currently describes how to workaround this problem.

[Ian Johnson (anonymouse67)]

Thanks for filing this bug.