broken libgit2 package in nixpkgs - Imported target "libgit2::libgit2package" includes non-existent path in its INTERFACE_INCLUDE_DIRECTORIES

i guess this is a downstream bug in nixpkgs
but maybe someone here cares to fix it

i can use libgit2 via pkg-config

cmake_minimum_required(VERSION 3.20)
project(git-file-times-project LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

find_package(PkgConfig REQUIRED)
pkg_check_modules(LIBGIT2 REQUIRED libgit2)

add_executable(git-file-times
    src/main.cpp
)

target_include_directories(git-file-times PRIVATE
    ${LIBGIT2_INCLUDE_DIRS}
)

target_link_directories(git-file-times PRIVATE
    ${LIBGIT2_LIBRARY_DIRS}
)

target_link_libraries(git-file-times PRIVATE
    ${LIBGIT2_LIBRARIES}
)

target_compile_options(git-file-times PRIVATE
    ${LIBGIT2_CFLAGS_OTHER}
)

but i cannot use libgit2 via cmake targets

cmake_minimum_required(VERSION 3.20)
project(git-file-times-project LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

find_package(libgit2 REQUIRED)

add_executable(git-file-times
    src/main.cpp
)

target_link_libraries(git-file-times PRIVATE
    libgit2::libgit2package
)

when i try to use libgit2 via cmake targets
cmake throws

CMake Error in CMakeLists.txt:
  Imported target "libgit2::libgit2package" includes non-existent path

    "/nix/store/ic7b9ni4f81807835k9cw3jb0ak31cpg-libgit2-1.9.2/include"

  in its INTERFACE_INCLUDE_DIRECTORIES.  Possible reasons include:

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

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and references files it does not
  provide.

/nix/store/n4912v5kzbc9bicq3pi865kdmhzdngxa-libgit2-1.9.2-dev/lib/cmake/libgit2/libgit2Targets.cmake

# The installation prefix configured by this project.
set(_IMPORT_PREFIX "/nix/store/ic7b9ni4f81807835k9cw3jb0ak31cpg-libgit2-1.9.2")

# Create imported target libgit2::libgit2package
add_library(libgit2::libgit2package SHARED IMPORTED)

set_target_properties(libgit2::libgit2package PROPERTIES
  INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
  INTERFACE_LINK_LIBRARIES "/nix/store/wbyqkb1vpm41s4jb8pv0i9h4jv08xdrv-openssl-3.6.1/lib/libssl.so;/nix/store/wbyqkb1vpm41s4jb8pv0i9h4jv08xdrv-openssl-3.6.1/lib/libcrypto.so;/nix/store/rqm937a4rpsa6qdb86slfjkvm7h4wjd5-llhttp-9.3.1/lib/libllhttp.so;/nix/store/khhzkpj9169ydnyg7jjrjx7s5ygdkcas-pcre2-10.46/lib/libpcre2-8.so;/nix/store/9lzm6krq5ikzbqbmazbh5jmzwph99rz3-libssh2-1.11.1/lib/libssh2.so;/nix/store/ixhlv41i2wpl84xgjcks061dz4yssbg3-zlib-1.3.2/lib/libz.so;rt"
)

_IMPORT_PREFIX should be the dev output of libgit2
/nix/store/n4912v5kzbc9bicq3pi865kdmhzdngxa-libgit2-1.9.2-dev

the dev output of libgit2 contains the header files

$ ls /nix/store/n4912v5kzbc9bicq3pi865kdmhzdngxa-libgit2-1.9.2-dev/include/
git2  git2.h

the main output of libgit2 contains only the git2 executable

$ find /nix/store/ic7b9ni4f81807835k9cw3jb0ak31cpg-libgit2-1.9.2 -type f
/nix/store/ic7b9ni4f81807835k9cw3jb0ak31cpg-libgit2-1.9.2/bin/git2

{ pkgs ? import <nixpkgs> {} }:
with pkgs;
mkShell {
  buildInputs = [
    cmake
    pkg-config
    libgit2
    # for libgit2
    openssl
    pcre2
    zlib
  ];
}

this is different from #7062

Start with the linked nixpkgs package.nix and compare its outputs with libgit2Targets.cmake in the reported dev store path. Reproduce the CMakeLists.txt example from the issue, then verify that the generated libgit2::libgit2package target references the output containing the headers and configures successfully.