package_project() does not normalize the install paths before printing

[ClausKlein]

my CMakeLists.txt contains this:

# ---- Create library ----

# Note: for header-only libraries change all PUBLIC flags to INTERFACE and create an interface
# target: add_library(${PROJECT_NAME} INTERFACE)
add_library(${PROJECT_NAME} ${headers} ${sources})
add_library(${PROJECT_NAME}::${PROJECT_NAME} ALIAS ${PROJECT_NAME})
target_compile_features(${PROJECT_NAME} PUBLIC cxx_std_20)

# being a cross-platform target, we enforce standards conformance on MSVC
target_compile_options(${PROJECT_NAME} PRIVATE "$<$<COMPILE_LANG_AND_ID:CXX,MSVC>:/permissive->")

# Link dependencies
target_link_libraries(${PROJECT_NAME} PUBLIC fmt::fmt)

# FIXME: should be PRIVATE! CK
target_link_libraries(${PROJECT_NAME} PUBLIC project_warnings project_options)

# target_include_directories with the SYSTEM modifier will request the compiler
# to omit warnings from the provided paths, if the compiler supports that
target_include_directories(
  ${PROJECT_NAME} SYSTEM PUBLIC $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
                                $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
)

if(CMAKE_SKIP_INSTALL_RULES)
  return()
endif()

# ---- Create an installable target ----
# this allows users to install and find the library via `find_package()`.

# Add other targets that you want installe here. Or be default we just package
# all targets recursively found for the current folder if not specified.
package_project(
  NAME ${PROJECT_NAME}
  TARGETS ${PROJECT_NAME} project_options project_warnings
  PUBLIC_INCLUDES ${PROJECT_SOURCE_DIR}/include
  PUBLIC_DEPENDENCIES_CONFIGURED "fmt 8.1.1"
  # FIXME: not yet used! PRIVATE_DEPENDENCIES_CONFIGURED project_options project_warnings
)

cmake -B ./build-ModernCmakeStarter-Debug -S /Users/clausklein/Workspace/cpp/ModernCmakeStarter/all -D OPT_ENABLE_COVERAGE=NO -DOPT_WARNINGS_AS_ERRORS=NO
-- CPM: adding package cxxopts@3.0.0 (v3.0.0 at /Users/clausklein/.cache/CPM/cxxopts/0c1df694f5ab3306e541038e6a2ed62926062894)
-- CPM: adding package greeter@ (/Users/clausklein/Workspace/cpp/ModernCmakeStarter/standalone/..)
-- CPM: greeter: adding package project_options@0.20.0 (v0.20.0 at /Users/clausklein/.cache/CPM/project_options/f4f28e0d6a43eb4247d834f6b906d21040cf1ef9)
-- CPM: greeter: adding package PackageProject.cmake@1.8.0 (v1.8.0 at /Users/clausklein/.cache/CPM/packageproject.cmake/987b02f8a9fe04de3c43e0e7a1afbb29c87adc5e)
-- Module support is disabled.
-- Version: 8.1.1
-- Build type: Debug
-- CXX_STANDARD: 20
-- Required features: cxx_variadic_templates
-- CPM: greeter: adding package fmt@8.1.1 (8.1.1 at /Users/clausklein/.cache/CPM/fmt/15c05aa781ab44fa13a906fe5737c1d14e5edee9)
-- Developer mode is ON. For production, use `-DENABLE_DEVELOPER_MODE:BOOL=OFF`. Building the project for the developer...
-- The default CMAKE_C_STANDARD used by external targets and tools is not set yet. Using the latest supported C standard that is 90
-- /usr/local/bin/ccache found and enabled
-- CPM: adding package doctest@2.4.8 (v2.4.8 at /Users/clausklein/.cache/CPM/doctest/367f22d2dff85570a9f727b99741f9e40b17df46)
-- CPM: adding package Format.cmake@1.7.3 (v1.7.3 at /Users/clausklein/.cache/CPM/format.cmake/17e103764947115e78d95ecc29c4bee54dc64e08)
-- CPM: adding package Greeter@ (/Users/clausklein/Workspace/cpp/ModernCmakeStarter/test/..)
-- CPM: adding package m.css@0 (a0d292ec311b97fefd21e93cdefb60f88d19ede6 at /Users/clausklein/.cache/CPM/m.css/23b42fe3166cf5c34c25c267ae0664557edd2200)
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/clausklein/Workspace/cpp/ModernCmakeStarter/build-ModernCmakeStarter-Debug
DESTDIR=/Users/clausklein/Workspace/cpp/stage cmake --install ./build-ModernCmakeStarter-Debug --prefix /usr
-- Install configuration: "Debug"
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/cmake/cxxopts/cxxopts-config.cmake
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/cmake/cxxopts/cxxopts-config-version.cmake
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/cmake/cxxopts/cxxopts-targets.cmake
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/cxxopts.hpp
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/pkgconfig/cxxopts.pc
-- Installing: /Users/clausklein/Workspace/cpp/stage/usr/lib/libfmtd.a
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/cmake/fmt/fmt-config.cmake
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/cmake/fmt/fmt-config-version.cmake
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/cmake/fmt/fmt-targets.cmake
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/cmake/fmt/fmt-targets-debug.cmake
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/args.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/chrono.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/color.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/compile.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/core.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/format.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/format-inl.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/locale.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/os.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/ostream.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/printf.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/ranges.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/include/fmt/xchar.h
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/lib/pkgconfig/fmt.pc
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/.//include
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/.//include/greeter
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/.//include/greeter/greeter.h
-- Installing: /Users/clausklein/Workspace/cpp/stage/usr/lib/libgreeter.a
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/share/greeter/greeterConfigVersion.cmake
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/share/greeter/greeterConfig.cmake
-- Old export file "/Users/clausklein/Workspace/cpp/stage/usr/share/greeter/greeterTargets.cmake" will be replaced.  Removing files [/Users/clausklein/Workspace/cpp/stage/usr/share/greeter/greeterTargets-debug.cmake].
-- Installing: /Users/clausklein/Workspace/cpp/stage/usr/share/greeter/greeterTargets.cmake
-- Installing: /Users/clausklein/Workspace/cpp/stage/usr/share/greeter/greeterTargets-debug.cmake
-- Installing: /Users/clausklein/Workspace/cpp/stage/usr/share/greeter/usage
-- # The package greeter provides the following CMake targets:

    find_package(greeter CONFIG REQUIRED)
    target_link_libraries(main PRIVATE  greeter::greeter greeter::project_options greeter::project_warnings)
  
bash-3.2$ 

This installed CMake config packages contains:

# Create imported target greeter::greeter
add_library(greeter::greeter STATIC IMPORTED)

set_target_properties(greeter::greeter PROPERTIES
  INTERFACE_COMPILE_FEATURES "cxx_std_20"
  INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
  INTERFACE_LINK_LIBRARIES "fmt::fmt;greeter::project_warnings;greeter::project_options"
  INTERFACE_SYSTEM_INCLUDE_DIRECTORIES "include"
)

# Create imported target greeter::project_options
add_library(greeter::project_options INTERFACE IMPORTED)

set_target_properties(greeter::project_options PROPERTIES
  INTERFACE_COMPILE_FEATURES "cxx_std_20"
  INTERFACE_COMPILE_OPTIONS "-fsanitize=address,undefined"
  INTERFACE_LINK_OPTIONS "-fsanitize=address,undefined"
)

# Create imported target greeter::project_warnings
add_library(greeter::project_warnings INTERFACE IMPORTED)

set_target_properties(greeter::project_warnings PROPERTIES
  INTERFACE_COMPILE_OPTIONS "\$<\$<COMPILE_LANGUAGE:CXX>:-Wall;-Wextra;-Wshadow;-Wnon-virtual-dtor;-Wold-style-cast;-Wcast-align;-Wunused;-Woverloaded-virtual;-Wpedantic;-Wconversion;-Wsign-conversion;-Wnull-dereference;-Wdouble-promotion;-Wformat=2;-Wimplicit-fallthrough>;\$<\$<COMPILE_LANGUAGE:C>:-Wall;-Wextra;-Wshadow;-Wcast-align;-Wunused;-Wpedantic;-Wconversion;-Wsign-conversion;-Wnull-dereference;-Wdouble-promotion;-Wformat=2;-Wimplicit-fallthrough>;\$<\$<COMPILE_LANGUAGE:CUDA>:-Wall;-Wextra;-Wunused;-Wconversion;-Wshadow>"
)
``


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[aminya]

Where is the strange part?

[ClausKlein]

-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/.//include
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/.//include/greeter
-- Up-to-date: /Users/clausklein/Workspace/cpp/stage/usr/.//include/greeter/greeter.h

And this info in not right:

cat: /Users/clausklein/Workspace/cpp/stage/usr/share/greeter/usage

    find_package(greeter CONFIG REQUIRED)
    target_link_libraries(main PRIVATE  greeter::greeter greeter::project_options greeter::project_warnings)

see

set_target_properties(greeter::greeter PROPERTIES
  INTERFACE_COMPILE_FEATURES "cxx_std_20"
  INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
  INTERFACE_LINK_LIBRARIES "fmt::fmt;greeter::project_warnings;greeter::project_options"
  INTERFACE_SYSTEM_INCLUDE_DIRECTORIES "include"
)

[aminya]

It seems correct to me. I don't see any issue here.

[ClausKlein]

It seems correct to me. I don't see any issue here.

Yes, "seems" it is correct, but may be prevented to be clear.
It looks strange in context of the other install messages. see normal-path

And https://discourse.cmake.org/t/target-include-directories-mylib-system-is-exported-without-import-prefix/5359 !

[ClausKlein]

The correct usage message should:

find_package(greeter CONFIG REQUIRED)
target_link_libraries(main PRIVATE greeter::greeter)

[aminya]

It seems correct to me. I don't see any issue here.

Yes, "seems" it is correct, but may be prevented to be clear. It looks strange in context of the other install messages. see normal-path

And discourse.cmake.org/t/target-include-directories-mylib-system-is-exported-without-import-prefix/5359 !

The reporting is just for information and debugging purposes. CMake itself should normalize the paths before installation if that is important for you.

[aminya]

target_link_libraries(main PRIVATE greeter::greeter)

That is subjective. When you export greeter::project_optinos, you cannot expect CMake to hide that target. Someone might really want to link with greeter::project_options.

However, it might be useful to add an option to hide this from the usage file.

[ClausKlein]

The correct usage message should:

find_package(greeter CONFIG REQUIRED)
target_link_libraries(main PRIVATE greeter::greeter)

This links fmt::fmt;greeter::project_warnings;greeter::project_options implicitly.