How can I leverage CMake to run my executable without copying resource files around?

There are a few ways to go about it.

1. Make your executable lookup with respect to a. Current working directory b. Executable's own directory
   • Advantage: works irrespective of the current working directory executable is invoked from
2. Symlink //assets directory to binary's //build/Debug, //build/Release, etc.

My personal choice is (1)(b) I usually do a POSTBUILD step with addcustomcommand(TARGET myexec ...), hard linking the built binary to project root where there's an assets directory.

addexecutable(myexecutable
  main.cpp
)
addcustomcommand(TARGET myexecutable
  POSTBUILD
  COMMAND ${CMAKECOMMAND} -E
  createhardlink $ ${PROJECTSOURCE_DIR}/$
  VERBATIM
)

Here's an actual example from one of my projects.