From building munit-plus on Travis CI (built with C++ 2011 on PGI C++ compiler):

pgc++  --c++11 -mp -o example munit.cpp example.cpp
munit.cpp:
"munit.cpp", line 596: warning: statement is unreachable
    return 0;
    ^
"munit.cpp", line 654: warning: statement is unreachable
    return 0;
    ^
"munit.cpp", line 714: warning: statement is unreachable
    return 0;
    ^

The relevant lines on this repository seem to be in clock/clock.h (commit 5834798):

• line 298 in psnip_clock_wall_get_time
• line 356 in psnip_clock_cpu_get_time
• line 416 in psnip_clock_monotonic_get_time

Feel free to label as wontfix.

Here is a link to the relevant build job on Travis CI: https://travis-ci.com/github/codylico/munit-plus/jobs/300147973

Here is a link to the GitHub repository for the project:
https://github.com/codylico/munit-plus