CMake issue: removing a folder with test files triggers recompilation

[ilfreddy]

Expected Behavior

Removing a a folder in the test suite should make CMake copy a fresh folder with updated test fils (I tried with tests/input). No executable or source file is affected and recompilation should therefore not be necessary.

Current Behavior

In addition to copying the folder (correct behavior) CMake recompiles some libraries.

Possible Solution

Steps to Reproduce (for bugs)

1. build the code
2. rm -rf build/tests/input
3. cd build
4. make

[robertodr]

The solution I can see is to make the copy operation a custom target upon which testing itself depends.
As a temporary workaround, touch CMakeLists.txt in the subdirectory of tests that you've modified.