autopkgtest failure in 0002-benchmark test

[Bryce Harrington]

From https://launchpad.net/ubuntu/+source/dbus-cpp/5.0.3-2, it looks like the build failed on all architectures except armhf, and on armhf there was a test failure:

https://autopkgtest.ubuntu.com/results/autopkgtest-impish/impish/armhf/d/dbus-cpp/20210708_173150_9b648@/log.gz

autopkgtest [17:31:26]: test 0002-benchmark: [-----------------------
DBus daemon: unix:abstract=/tmp/dbus-r1vtLBVT2b,guid=9e9dc7c56358b39bba3cf32260e73670

(dbus-test-runner:1285): libdbustest-WARNING **: 17:31:28.819: Unable to start process '/usr/lib/*/dbus-cpp/examples/benchmark/benchmark': Failed to execute child process ?/usr/lib/*/dbus-cpp/examples/benchmark/benchmark? (No such file or directory)
task-0: Shutting down
DBus daemon: Shutdown
autopkgtest [17:31:29]: test 0002-benchmark: -----------------------]
0002-benchmark FAIL non-zero exit status 253

Debian is seeing the same test failures in their CI framework:

https://ci.debian.net/data/autopkgtest/unstable/amd64/d/dbus-cpp/14056784/log.gz
https://ci.debian.net/data/autopkgtest/unstable/arm64/d/dbus-cpp/14058472/log.gz