How to not make install step when building externa

Question

I'm building dependency project with cmake ExternalProject_Add command:

include(ExternalProject)
...
set(COMMON_BASE_PROJECT_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../CommonBase)

ExternalProject_Add(CommonBaseProject
  SOURCE_DIR ${COMMON_BASE_PROJECT_DIR}
  BINARY_DIR ${COMMON_BASE_PROJECT_DIR}/build
  INSTALL_COMMMAND ""
)   

include_directories(${CMAKE_CURRENT_SOURCE_DIR}/include)
include_directories(${COMMON_BASE_PROJECT_DIR}/include)

add_library(
    ${LIBRARY_NAME}
    SHARED
    ${SRC_FILES}
    ${INCLUDE_FILES}
)

target_link_libraries (Bios ${COMMON_BASE_PROJECT_DIR}/build/libCommonBase.dll)
add_dependencies(Bios CommonBaseProject)

but i get error:

[100%] Linking CXX shared library libCommonBase.dll
[100%] Built target CommonBase
[ 50%] Performing install step for 'CommonBaseProject'
make[3]: *** No rule to make target 'install'.  Stop.

I don't need to make install step, so my question is: how to disable it?

Answer 1

You almost had it: Instead of INSTALL_COMMAND "" put something like

    INSTALL_COMMAND cmake -E echo "Skipping install step."

Answer 2

You can generate a target for the build step with STEP_TARGETS build and add dependency on this particular target. The step targets are named <external-project-name>-<step-name> so in this case the target representing the build step will be named CommonBaseProject-build.

You probably also want to exclude the CommonBaseProject from the "all" target with EXCLUDE_FROM_ALL TRUE.

ExternalProject_Add(CommonBaseProject
  SOURCE_DIR ${COMMON_BASE_PROJECT_DIR}
  BINARY_DIR ${COMMON_BASE_PROJECT_DIR}/build
  STEP_TARGETS build
  EXCLUDE_FROM_ALL TRUE
)

add_dependencies(Bios CommonBaseProject-build)

Answer 3

Not relevant to your question, which it was already answered, but in my case I had the following ExternalProject_Add directive:

ExternalProject_Add(external_project
    # [...]
    # Override build/install command
    BUILD_COMMAND ""
    INSTALL_COMMAND
        "${CMAKE_COMMAND}"
        --build .
        --target INSTALL    # Wrong casing for "install" target
       --config ${CMAKE_BUILD_TYPE}
)

In this case cmake quits with very similar error (*** No rule to make target 'INSTALL'), but in this case it's the external project that is looking for incorrect uppercase INSTALL target: correct case is install instead. Apparently, that worked in Windows with MSVC but fails in unix operating systems.