How to not make install step when building external project with cmake - cmake

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.

Answer 4

Since at least CMake 3.10 the empty string is sufficient to suppress the install step:
Passing an empty string as the <cmd> makes the install step do nothing.
The same goes for the other stages; see the docs for more.
If you're still building with CMake <3.10 then you need to update CMake ;)