Running unit tests under root fails

[viktormalik]

Running unit tests under root fails the utils.file_exists_and_ownedby_root test:

# tests/bpftrace_test --gtest_filter="utils.file_exists_and_ownedby_root"
Note: Google Test filter = utils.file_exists_and_ownedby_root
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from utils
[ RUN      ] utils.file_exists_and_ownedby_root
/home/vmalik/src/bpf/bpftrace/tests/utils.cpp:375: Failure
Value of: file_exists_and_ownedby_root((tmpdir + file1).c_str())
  Actual: true
Expected: false
[  FAILED  ] utils.file_exists_and_ownedby_root (0 ms)
[----------] 1 test from utils (0 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (0 ms total)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] utils.file_exists_and_ownedby_root

 1 FAILED TEST

The reason is that the test expects files created by a non-root user.

I'm used to run all the tests under the root so that's how I discovered this problem. I'm not sure if that's the expected workflow, though.