### Author:  [@jviotti](https://discourse.cmake.org/u/jviotti)
#### Post date: [July 6, 2023, 7:19pm UTC](https://discourse.cmake.org/t/path-declared-in-interface-include-directories-imported-target-seemingly-not-found/8475/1 "2023-07-06T19:19:58Z")
I’m working on a C++ project that exports a bunch of libraries and tries to make use of `CMakePackageConfigHelpers` to be findable using `find_package`. After installation, projects attempting to make use of it, like:
```auto
cmake_minimum_required(VERSION 3.18)
project(jsontoolkit_hello VERSION 0.0.1 LANGUAGES CXX)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
find_package(JSONToolkit REQUIRED)
add_executable(jsontoolkit_hello hello.cc)
target_link_libraries(jsontoolkit_hello PRIVATE sourcemeta::jsontoolkit::json)
```
Face the following error:
```auto
CMake Error in CMakeLists.txt:
Imported target "sourcemeta::jsontoolkit::json" includes non-existent path
"/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.
```
The `find_package` command correctly finds JSONToolkit, which on my system is located at: `/lib/cmake/jsontoolkit/JSONToolkitConfig.cmake`. I can confirm this file is getting loaded if add any `message()` commands to it. This file does the following:
```auto
include("${CMAKE_CURRENT_LIST_DIR}/sourcemeta_jsontoolkit_json.cmake")
```
Which is located at `lib/cmake/jsontoolkit/sourcemeta_jsontoolkit_json.cmake` and correctly gets loaded. This file contains the following:
```auto
set_target_properties(sourcemeta::jsontoolkit::json PROPERTIES
INTERFACE_COMPILE_DEFINITIONS "JSONTOOLKIT_BACKEND_RAPIDJSON"
INTERFACE_COMPILE_OPTIONS "<..............>"
INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
INTERFACE_LINK_LIBRARIES "rapidjson"
)
```
If I print `${_IMPORT_PREFIX}/include` next to this declaration, I get: `/Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist/include`, which exists and matches the expected prefix:
```auto
$ tree /Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist/include
/Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist/include
└── jsontoolkit
├── json
│ ├── iterators.h
│ ├── rapidjson
│ │ ├── common.h
│ │ ├── iterators.h
│ │ ├── read.h
│ │ └── write.h
│ ├── read.h
│ └── write.h
├── json.h
├── jsonschema
│ └── resolver.h
└── jsonschema.h
5 directories, 10 files
```
So why can’t CMake find it? I can confirm the error is around the `INTERFACE_INCLUDE_DIRECTORIES`, as if I modify the declaration of that line, the error message is reflected accordingly.
Am I missing anything?
Relevant links, in case its useful:
- Repository and commit (in case you want to try it out locally): [GitHub - sourcemeta/jsontoolkit at ed13d9a696b8de53d44713ae832ca13892a65326](https://github.com/sourcemeta/jsontoolkit/tree/ed13d9a696b8de53d44713ae832ca13892a65326)
- Declaration of the `sourcemeta::jsontoolkit::json` library: [https://github.com/sourcemeta/jsontoolkit/blob/ed13d9a696b8de53d44713ae832ca13892a65326/src/json/CMakeLists.txt](https://github.com/sourcemeta/jsontoolkit/blob/ed13d9a696b8de53d44713ae832ca13892a65326/src/json/CMakeLists.txt)
- Config in file: [https://github.com/sourcemeta/jsontoolkit/blob/ed13d9a696b8de53d44713ae832ca13892a65326/cmake/JSONToolkitConfig.cmake.in](https://github.com/sourcemeta/jsontoolkit/blob/ed13d9a696b8de53d44713ae832ca13892a65326/cmake/JSONToolkitConfig.cmake.in)
Here is a GitHub Actions run highlighting steps being ran and a full example of the error: [Make the project consumable by CMake `find_package()` · sourcemeta/jsontoolkit@ed13d9a · GitHub](https://github.com/sourcemeta/jsontoolkit/actions/runs/5470587856/jobs/9960837570)
---
### Author:  [@craig.scott](https://discourse.cmake.org/u/craig.scott)
#### Post date: [July 7, 2023, 4:53am UTC](https://discourse.cmake.org/t/path-declared-in-interface-include-directories-imported-target-seemingly-not-found/8475/2 "2023-07-07T04:53:40Z")
Perhaps check whether something else may be changing the value of the `INTERFACE_INCLUDE_DIRECTORIES` property on the `sourcemeta::jsontoolkit::json` target. The output logged in the error suggests that the value of that property is just `/include`. Try printing the value of that property from your own project as late as possible to check.
---
### Author:  [@jviotti](https://discourse.cmake.org/u/jviotti)
#### Post date: [July 7, 2023, 1:40pm UTC](https://discourse.cmake.org/t/path-declared-in-interface-include-directories-imported-target-seemingly-not-found/8475/3 "2023-07-07T13:40:21Z")
From what I can tell, CMake will automatically replace the prefix directory (set with `CMAKE_PREFIX_PATH`) with `/` (perhaps for better readability?)
What I’m doing is:
- Install the library in question under `/Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist` through `cmake --install`
- Configure the project trying to utilize the library (with `find_package()`) by passing an appropriate prefix path through `cmake -S <...> -B <...> -DCMAKE_PREFIX_PATH=Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist`
The generated target export from my library has this:
```auto
INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
```
Which results in the error being printed as `/include`. If I change it to `${_IMPORT_PREFIX}/xxx`, I get the following (notice the absolute path):
```auto
CMake Error in CMakeLists.txt:
Imported target "sourcemeta::jsontoolkit::json" includes non-existent path
"/Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist/xxx"
in its INTERFACE_INCLUDE_DIRECTORIES. Possible reasons include:
```
If I hardcode the right path as follows:
```auto
INTERFACE_INCLUDE_DIRECTORIES "/Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist/include"
```
That again gets printed as it originally was:
```auto
CMake Error in CMakeLists.txt:
Imported target "sourcemeta::jsontoolkit::json" includes non-existent path
"/include"
in its INTERFACE_INCLUDE_DIRECTORIES. Possible reasons include:
```
So there seems to be some replacement going on that I don’t fully understand.
---
### Author:  [@jviotti](https://discourse.cmake.org/u/jviotti)
#### Post date: [July 7, 2023, 8:33pm UTC](https://discourse.cmake.org/t/path-declared-in-interface-include-directories-imported-target-seemingly-not-found/8475/4 "2023-07-07T20:33:09Z")
I also tried fetching the `INTERFACE_INCLUDE_DIRECTORIES` of the imported target on the CMake project making use of it, and even then the path is correct, and exists:
```auto
get_target_property(X sourcemeta::jsontoolkit::json INTERFACE_INCLUDE_DIRECTORIES)
message(STATUS "${X}")
```
This prints:
```auto
/Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist/include
```
Which definitely exists:
```auto
$ tree /Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist/include
/Users/jviotti/Projects/sourcemeta/jsontoolkit/build/dist/include
└── jsontoolkit
├── json
│ ├── iterators.h
│ ├── rapidjson
│ │ ├── common.h
│ │ ├── iterators.h
│ │ ├── read.h
│ │ └── write.h
│ ├── read.h
│ └── write.h
├── json.h
├── jsonschema
│ └── resolver.h
└── jsonschema.h
```
It is very weird that it complains it doesn’t exist.
---
### Author:  [@jviotti](https://discourse.cmake.org/u/jviotti)
#### Post date: [July 10, 2023, 9:34pm UTC](https://discourse.cmake.org/t/path-declared-in-interface-include-directories-imported-target-seemingly-not-found/8475/5 "2023-07-10T21:34:30Z")
I found the problem. The error is highly misleading. The include directory being corrupted was on a dependency of the interface library in question, where a CMake variable was getting expanded to anything.
It was a project problem, and easy to spot once past the confusing error. Ideally, the error message would point at the right library.