Potentially pax/grsec related difference.

===> Failed tests
utils/stacktrace_test:dump_stacktrace__integration  ->  failed: Line 391: atf::utils::grep_file("#0", exit_handle.stderr_file().str()) not met  [0.008s]
utils/stacktrace_test:dump_stacktrace__ok  ->  failed: Line 420: atf::utils::grep_file("^frame 1$", exit_handle.stderr_file().str()) not met  [0.008s]
utils/stacktrace_test:dump_stacktrace_if_available__append  ->  failed: Line 560: atf::utils::grep_file("frame 1", exit_handle.stderr_file().str()) not met  [0.008s]
utils/stacktrace_test:find_core__found__long  ->  failed: Core dumped, but no candidates found  [0.004s]
utils/stacktrace_test:find_core__found__short  ->  failed: Core dumped, but no candidates found  [0.004s]