How to set library path for CTest when building package with dpkg-builpackage?

I'm using CTest in my project. I added simple script to run tests as POST_BUILD. Everything works fine when i build project with make.

The interesting part starts when I'm building package with dpkg-buildpackage. CTest seems to look for libraries in system directories instead of using a currently built one. Is there a way to tell CTest or dpkg-buildpackage to use a currently built library while executing tests?

CMake macro i use:

add_executable(example tests/example.cpp)
target_link_libraries(example my_lib)
enable_testing()

macro(add_unit_test target test)
    list(APPEND tests ${test})
    add_test(${target} ${test})
endmacro(add_unit_test)

add_unit_test(test_example example)

add_custom_target(all_tests ALL DEPENDS ${tests})

add_custom_command(
    TARGET all_tests
    COMMENT "Run tests"
    POST_BUILD COMMAND ctest ARGS --output-on-failure
    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
)

Solution

Okay, so i've figured it out. Because my lib compiles in CMAKE_BINARY_DIR, all i needed is to add LD_LIBRARY_PATH prorerty to every test in project.

So macro now looks like this:

macro(add_unit_test target test)
    list(APPEND tests ${test})
    add_test(${target} ${test})
    set_property(TEST ${target} PROPERTY ENVIRONMENT "LD_LIBRARY_PATH=${CMAKE_BINARY_DIR}")
endmacro(add_unit_test)