[editable] Have CMAKE_PREFIX_PATH point to the build directory

[pleroux0]

Hi

If I have an editable package: is it possible to add the build directory of an editable package to CMAKE_PREFIX_PATH? If it is not possible, consider this a feature request.

My use case:

My CMake project defines a dummy Config file in the build directory so that I can add my dependencies with either add_subdirectory (like conan workspace does) or find_package (modern CMake approach). There is no standard CMake approach to do this yet. If I can have conan modify CMAKE_PREFIX_PATH so that the dummy config is findable with find_package then I any CMake project that calls find_package(MyEditablePackage) will "find" the editable package.

---

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[lasote]

Hi! if you use the cmake_paths generator in the conan install command, it will generate the conan_paths.cmake pointing to any [builddirs] specified in your editable package layout.
So if you declare:

[builddirs]
build

You will get:

set(CMAKE_MODULE_PATH "/path/to/conan-zlib/build/" ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_LIST_DIR})
set(CMAKE_PREFIX_PATH "/path/to/conan-zlib/build/" ${CMAKE_PREFIX_PATH} ${CMAKE_CURRENT_LIST_DIR})

[pleroux0]

Hi.

Thanks for the response.

As soon as I specify a layout file conan (1.13.2) crashes.

Steps to reproduce with minimal example:

• clone the conan examples
• go to the examples/workspace/cmake/say directory
• Set say as editable: conan editable add . say/0.1@user/testing --layout ../layout_gcc
• create and go to the examples/workspace/cmake/hello/build directory
• Run conan install

The output is

Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=gcc
compiler.libcxx=libstdc++
compiler.version=8
os=Linux
os_build=Linux
[options]
[build_requires]
[env]

conanfile.py (hello/0.1@None/None): Installing package
Requirements
    say/0.1@user/testing from user folder - Editable
Packages
    say/0.1@user/testing:2d5685a99e2ff5a0d2b054bb1fbfa46781f8a46a - Editable

say/0.1@user/testing: Generator cmake created conanbuildinfo.cmake
say/0.1@user/testing: Generated conaninfo.txt
Traceback (most recent call last):
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/model/ref.py", line 111, in loads
    _, name, version, user, channel, revision, _ = ConanFileReference.sep_pattern.split(text)
ValueError: not enough values to unpack (expected 7, got 1)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/command.py", line 376, in install
    ref = ConanFileReference.loads(args.path_or_reference)
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/model/ref.py", line 114, in loads
    "OpenCV/1.0.6@user/stable" % text)
conans.errors.ConanException: Wrong package recipe reference ..
Write something like OpenCV/1.0.6@user/stable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/command.py", line 1570, in run
    method(args[0][1:])
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/command.py", line 389, in install
    install_folder=args.install_folder)
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/conan_api.py", line 93, in wrapper
    return f(*args, **kwargs)
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/conan_api.py", line 572, in install
    no_imports=no_imports)
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/manager.py", line 80, in install
    installer.install(deps_graph, keep_build)
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/installer.py", line 270, in install
    self._build(nodes_by_level, deps_graph, keep_build, root_node, graph_info)
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/installer.py", line 286, in _build
    self._handle_node_editable(node, graph_info)
  File "/home/pleroux/.local/lib/python3.7/site-packages/conans/client/installer.py", line 328, in _handle_node_editable
    graph_info.save(build_folder)
AttributeError: 'NoneType' object has no attribute 'save'

ERROR: 'NoneType' object has no attribute 'save'

If the --layout ../layout_gcc is omitted then the conan install works.

output:

Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=gcc
compiler.libcxx=libstdc++
compiler.version=8
os=Linux
os_build=Linux
[options]
[build_requires]
[env]

conanfile.py (hello/0.1@None/None): Installing package
Requirements
    say/0.1@user/testing from user folder - Editable
Packages
    say/0.1@user/testing:2d5685a99e2ff5a0d2b054bb1fbfa46781f8a46a - Editable

conanfile.py (hello/0.1@None/None): Generator cmake created conanbuildinfo.cmake
conanfile.py (hello/0.1@None/None): Generator txt created conanbuildinfo.txt
conanfile.py (hello/0.1@None/None): Generated conaninfo.txt
conanfile.py (hello/0.1@None/None): Generated graphinfo

[pleroux0]

Also happens with the conan in the devel branch. Should I open a new issue for this?

[pleroux0]

I think my issue is a duplicate of #4819.

[lasote]

Yes, it is a duplicate of that. I suggest to remove the "build_folder" entry in the layout and try again, we are already working to see how to fix that.

[pleroux0]

Yes, it works without build_folder. Setting [builddirs] does modify the CMake prefix path. I appreciate your time. My question is resolved and I'll close the issue.