CMake config file references files with wrong path

[Elvis Stansvik]

I tried to use this package when building VTK from source, by passing the flag

    -Dpugixml_DIR=/usr/share/libpugixml-dev/cmake

to the CMake configure step. This failed with

CMake Error at /usr/share/libpugixml-dev/cmake/pugixml-config.cmake:87 (message):
  The imported target "pugixml" references the file

     "/lib/x86_64-linux-gnu/libpugixml.so.1.8"

  but this file does not exist. Possible reasons include:

  * The file was deleted, renamed, or moved to another location.

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and contained

     "/usr/share/libpugixml-dev/cmake/pugixml-config.cmake"

  but not all the files it references.

Call Stack (most recent call first):
  CMake/vtkModuleMacros.cmake:891 (find_package)
  ThirdParty/pugixml/CMakeLists.txt:1 (vtk_module_third_party)

Looking at /usr/share/libpugixml-dev/cmake/pugixml-config.cmake, this section of code:

# Compute the installation prefix relative to this file.
get_filename_component(_IMPORT_PREFIX "${CMAKE_CURRENT_LIST_FILE}" PATH)
# Use original install prefix when loaded through a
# cross-prefix symbolic link such as /lib -> /usr/lib.
get_filename_component(_realCurr "${_IMPORT_PREFIX}" REALPATH)
get_filename_component(_realOrig "/usr/lib/x86_64-linux-gnu/cmake/pugixml" REALPATH)
if(_realCurr STREQUAL _realOrig)
  set(_IMPORT_PREFIX "/usr/lib/x86_64-linux-gnu/cmake/pugixml")
endif()
unset(_realOrig)
unset(_realCurr)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
if(_IMPORT_PREFIX STREQUAL "/")
  set(_IMPORT_PREFIX "")
endif()

seems to arrive at a ${_IMPORT_PREFIX} of "", which means e.g.

set_target_properties(pugixml PROPERTIES
  IMPORTED_LOCATION_NOCONFIG "${_IMPORT_PREFIX}/lib/x86_64-linux-gnu/libpugixml.so.1.8"
  IMPORTED_SONAME_NOCONFIG "libpugixml.so.1"
  )

in /usr/share/libpugixml-dev/cmake/pugixml-config-noconfig.cmake will become wrong ("/lib/x86_64-linux-gnu/libpugixml.so.1"), leading to config error.

Looks like the calculation of ${_IMPORT_PREFIX} is wrong, not sure if this is because of some wrong assumption that doesn't hold.

Seems to make it impossible to use this package from a CMake-using project (using -Dpugixml_DIR).

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Gianfranco Costamagna (costamagnagianfranco)]

Hello, I think this bug should be reported upstream! can you please do it?

[Gianfranco Costamagna (costamagnagianfranco)]

This should be fixed at least in Ubuntu jammy

cat ../CMakeLists.txt
cmake_minimum_required(VERSION 3.22)
project(test)
find_package(pugixml REQUIRED)
add_executable(test test.cpp)
target_link_libraries(test pugixml)

cat ../test.cpp
#include <pugixml.hpp>
#include <stdio.h>
int main()
{
 printf("%d\n",PUGIXML_VERSION);
}

$ cmake ..
-- The C compiler identification is GNU 11.2.0
-- The CXX compiler identification is GNU 11.2.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /foo/bar

# make VERBOSE=1
/usr/bin/cmake -S/foo -B/foo/bar --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /foo/bar/CMakeFiles /foo/bar//CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory '/foo/bar'
make -f CMakeFiles/test.dir/build.make CMakeFiles/test.dir/depend
make[2]: Entering directory '/foo/bar'
cd /foo/bar && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /foo /foo /foo/bar /foo/bar /foo/bar/CMakeFiles/test.dir/DependInfo.cmake --color=
make[2]: Leaving directory '/foo/bar'
make -f CMakeFiles/test.dir/build.make CMakeFiles/test.dir/build
make[2]: Entering directory '/foo/bar'
[ 50%] Building CXX object CMakeFiles/test.dir/test.cpp.o
/usr/bin/c++ -MD -MT CMakeFiles/test.dir/test.cpp.o -MF CMakeFiles/test.dir/test.cpp.o.d -o CMakeFiles/test.dir/test.cpp.o -c /foo/test.cpp
[100%] Linking CXX executable test
/usr/bin/cmake -E cmake_link_script CMakeFiles/test.dir/link.txt --verbose=1
/usr/bin/c++ CMakeFiles/test.dir/test.cpp.o -o test /usr/lib/x86_64-linux-gnu/libpugixml.so.1.12
make[2]: Leaving directory '/foo/bar'
[100%] Built target test
make[1]: Leaving directory '/foo/bar'
/usr/bin/cmake -E cmake_progress_start /foo/bar/CMakeFiles 0
# ./test
1120