gcovr: RuntimeError: GCOV returncode was 5.

Problem

After executing the instrumented code

gcovr -r . --html-details -o coverage/index.html

fails with no output from

gcov

and a Python RuntimeError that says GCOV returncode was 5.

Solution 1

In one case a full clean of the relevant build directory and a rebuild and rerun was enough to fix the issue. Added 2024-01-17

Solution 2

In another case the first solution was not enough. Rerunning gcovr with --verbose prints the failing gcov command line and running the underlying gcov command manually revealed that it was trying to process a .gcda file without a corresponding .gcno file. In this case the offending file was part of a library that was not interesting to include in the final report and adding the correct --exclude-directories flag to gcovr solved the returncode 5 issue. Added 2024-01-17