The related test from kyua consistently shows an expected failure.
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20160301-031439 I 58919 utils/cmdline/ui.cpp:103: stdout: lib/libc/locale/mbtowc_test:mbtowc ->
20160301-031439 I 58919 engine/scheduler.cpp:1084: Spawning /usr/tests/lib/libc/locale/mbtowc_test:mbtowc
20160301-031439 I 58919 utils/process/executor.cpp:774: Spawned subprocess with exec_handle 87696
20160301-031439 I 58919 utils/process/executor.cpp:630: Waited for subprocess with exec_handle 87696
20160301-031439 I 58919 utils/process/executor.cpp:368: Cleaning up exit_handle for exec_handle 87696
20160301-031439 I 58919 utils/cmdline/ui.cpp:103: stdout: expected_failure: zh_CN.GB18030: /usr/src/contrib/netbsd-tests/lib/libc/locale/t_mbtowc.c:122: ret != (size_t)-1 not met [0.004s]
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