fuchsia-lockfilefuchsia-lockfile is a host library that coordinates file access from multiple processes.
Since this is a host library, the host toolchain needs to be specified for the target. For a x64, to add tests for this library to your build, append the following to the fx set: --with //src/lib/fuchsia-lockfile:host_tests\(//build/toolchain:host_x64\).
To run the tests:
fx test //src/lib/fuchsia-lockfile