CMake Error: install(EXPORT "ProjectTargets" ...) includes target "xxx" which requires target "yyy" that is not in any export set.

Code
1

Why does my project with static libs NOT work, but with shared libs it works?

clausklein$ cmake --version
cmake version 3.25.0

bash-3.2$ make build
cmake -B ../build-agent++-4.5.1-x86_64-Debug -S . -G Ninja -D BUILD_SHARED_LIBS=NO
-- agent++ Version 4.5.1
-- Found AGENTPP_OPAQUE_PTHREAD_T: long
-- snmp++ Version 3.4.7
-- Found int64_t: int64_t
-- Found uint64_t: uint64_t
-- CPM: snmp_pp: adding package project_options@0.26.3 (v0.26.3 at /Users/clausklein/.cache/CPM/project_options/14755ed2f1a70e93687929554b166873eba6ebc1)
-- Found OpenSSL (include: /usr/local/opt/openssl/include, library: /usr/local/opt/openssl/lib/libssl.dylib;/usr/local/opt/openssl/lib/libcrypto.dylib)
-- The default CMAKE_C_STANDARD used by external targets and tools is not set yet. Using the latest supported C standard that is 17
-- /usr/local/bin/ccache found and enabled
-- CPM: snmp_pp: adding package PackageProject.cmake@1.10.0 (v1.10.0 at /Users/clausklein/.cache/CPM/packageproject.cmake/41b1a5028ad2c8d2c6bb64eb6beff8b090d304e5)
-- CPM: adding package snmp_pp@0 (fba56ad02f6609c4940f1eb0f47b7c0ac43cb326 at /Users/clausklein/.cache/CPM/snmp_pp/f4ab8c03c0d58410763233c4975837896ba64680)
-- The default CMAKE_C_STANDARD used by external targets and tools is not set yet. Using the latest supported C standard that is 17
-- /usr/local/bin/ccache found and enabled
-- Configuring done
CMake Error: install(EXPORT "agent_ppTargets" ...) includes target "agent_pp" which requires target "agent_pp_project_options" that is not in any export set.
CMake Error: install(EXPORT "agent_ppTargets" ...) includes target "agent_pp" which requires target "agent_pp_project_warnings" that is not in any export set.
CMake Error: install(EXPORT "snmp_ppTargets" ...) includes target "snmp_pp" which requires target "snmp_pp_project_options" that is not in any export set.
CMake Error: install(EXPORT "snmp_ppTargets" ...) includes target "snmp_pp" which requires target "snmp_pp_project_warnings" that is not in any export set.
-- Generating done
CMake Generate step failed.  Build files cannot be regenerated correctly.
make: *** [../build-agent++-4.5.1-x86_64-Debug/compile_commands.json] Error 1
bash-3.2$ make build
cmake -B ../build-agent++-4.5.1-x86_64-Debug -S . -G Ninja -D BUILD_SHARED_LIBS=YES
-- agent++ Version 4.5.1
-- Found AGENTPP_OPAQUE_PTHREAD_T: long
-- snmp++ Version 3.4.7
-- Found int64_t: int64_t
-- Found uint64_t: uint64_t
-- CPM: snmp_pp: adding package project_options@0.26.3 (v0.26.3 at /Users/clausklein/.cache/CPM/project_options/14755ed2f1a70e93687929554b166873eba6ebc1)
-- Found OpenSSL (include: /usr/local/opt/openssl/include, library: /usr/local/opt/openssl/lib/libssl.dylib;/usr/local/opt/openssl/lib/libcrypto.dylib)
-- The default CMAKE_C_STANDARD used by external targets and tools is not set yet. Using the latest supported C standard that is 17
-- /usr/local/bin/ccache found and enabled
-- CPM: snmp_pp: adding package PackageProject.cmake@1.10.0 (v1.10.0 at /Users/clausklein/.cache/CPM/packageproject.cmake/41b1a5028ad2c8d2c6bb64eb6beff8b090d304e5)
-- CPM: adding package snmp_pp@0 (fba56ad02f6609c4940f1eb0f47b7c0ac43cb326 at /Users/clausklein/.cache/CPM/snmp_pp/f4ab8c03c0d58410763233c4975837896ba64680)
-- The default CMAKE_C_STANDARD used by external targets and tools is not set yet. Using the latest supported C standard that is 17
-- /usr/local/bin/ccache found and enabled
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/clausklein/Downloads/Software/agentpp/build-agent++-4.5.1-x86_64-Debug
bash-3.2$ 
``
2

NOTE: I use the project_options cmake package PRIVATE

project_options(
  PREFIX
  ${PROJECT_NAME}
  ENABLE_CACHE
  ${ENABLE_COVERAGE}
  ${ENABLE_UNITY}
  # ENABLE_SANITIZER_ADDRESS
  # ENABLE_SANITIZER_UNDEFINED_BEHAVIOR
  ENABLE_SANITIZER_THREAD
  # ENABLE_SANITIZER_MEMORY
  # TODO: WARNINGS_AS_ERRORS
)

option(BUILD_SHARED_LIBS "Global flag to cause add_library() to create shared libraries if on." ON)
add_library(${PROJECT_NAME} ${MY_HEADER_FILES} ${MY_HEADER_LIB_FILES} ${CMAKE_CURRENT_BINARY_DIR}/config.h ${MY_SRC_FILES})
target_link_libraries(${PROJECT_NAME} PRIVATE ${PROJECT_NAME}_project_options ${PROJECT_NAME}_project_warnings)
set_target_properties(${PROJECT_NAME} PROPERTIES UNITY_BUILD ${ENABLE_UNITY})
3

For static libraries, PRIVATE link dependencies are added to the export set using $<LINK_ONLY:> so that any symbols they provide are given to consumers (since the static library won’t contain them). Starting with CMake 3.25, you can use $<BUILD_LOCAL_INTERFACE:${PROJECT_NAME}_project_options> to hide the target from all exports. Before that, you have $<BUILD_INTERFACE> to at least hide it from the install export (but it still needs to be in the build export).

4

Do you mean starting with v3.26?
see https://gitlab.kitware.com/cmake/cmake/-/merge_requests/7919/diffs#efc7fdbbaf6edb39bddabbebc78e6d86bd0b3dc0

5

That is not clear to me!

I use only this now:

set(PROJECT_WARNINGS_CXX -Wall -Wextra -Wno-unused-parameter)
add_library(${PROJECT_NAME}_mywarnings INTERFACE)
target_compile_options(
  ${PROJECT_NAME}_mywarnings
  INTERFACE $<$<COMPILE_LANGUAGE:CXX>:${PROJECT_WARNINGS_CXX}>
)
set(LIST_OF_SANITIZERS address)
add_library(${PROJECT_NAME}_myoptions INTERFACE)
if(NOT MSVC)
  target_compile_options(${PROJECT_NAME}_myoptions INTERFACE -fsanitize=${LIST_OF_SANITIZERS})
  target_link_options(${PROJECT_NAME}_myoptions INTERFACE -fsanitize=${LIST_OF_SANITIZERS})
  target_compile_options(${PROJECT_NAME}_myoptions INTERFACE --coverage -O0 -g)
  target_link_libraries(${PROJECT_NAME}_myoptions INTERFACE --coverage)
endif()

add_library(${PROJECT_NAME} ${MY_HEADER_FILES} ${MY_HEADER_LIB_FILES} ${CMAKE_CURRENT_BINARY_DIR}/config.h ${MY_SRC_FILES})
target_link_libraries(${PROJECT_NAME} PRIVATE ${PROJECT_NAME}_myoptions ${PROJECT_NAME}_mywarnings)
6

Err, yes, sorry.

To use it:

target_link_libraries(${PROJECT_NAME}
  PRIVATE
    "$<BUILD_INTERFACE:${PROJECT_NAME}_myoptions>"
    "$<BUILD_INTERFACE:${PROJECT_NAME}_mywarnings>")

Replace BUILD_INTERFACE with BUILD_LOCAL_INTERFACE once you can assume CMake 3.26.