I wrote about meson the awesome build system before. For C-based projects with many test executables there is nice infrastructure, however many C++ projects probably use Google Test or Catch and a single binary which runs the entire test suite. This is all nice and dandy with Google Test if you compile and link the test executable straight from the unit test source files. If however you build intermediate static libraries for organizational reasons you will quickly notice that Google Test won’t run anything at all because the symbols from Google Test itself won’t end up in the final binary without specifying the --whole-archive flag. Luckily, meson got the link_whole parameter since version 0.46, so instead of declaring your static test library as

test_lib = static_library('testlib',
  sources: test_sources,
  dependencies: [gtest_dep] + build_deps,
)

test_dep = declare_dependency(
  link_with: test_lib,
  dependencies: other_deps,
)

test_binary = executable('testfoo',
  sources: ['main.cpp'],
  dependencies: [test_dep],
)

you would change test_dep to

test_dep = declare_dependency(
  link_whole: test_lib,
  dependencies: other_deps,
)

and run your tests as usual.