Conan with cmake-conan missing conanbuild.conf - c++

Question

I am want to package a CMake project with conan.
For that I use the following conanfile.py:
import os
from conans import ConanFile, tools
from conan.tools.cmake import CMake, CMakeToolchain
from conans.tools import Version
class BaseLibrary(ConanFile):
name = "base-library"
version = "1.0.0"
description = """This is a test project with a library base::io
and base::math and an executable cli."""
license = "MIT"
generators = "cmake_find_package_multi", "cmake_find_package",
default_options = {"fmt:shared": True}
build_policy = "missing" # if this package is build by default if missing.
settings = "os", "compiler", "build_type", "arch"
exports_sources = "*"
_cmake = None
def requirements(self):
if Version(self.version) >= "1.0.0":
self.requires("fmt/8.0.1")
def _configure_cmake(self):
if self._cmake:
return self._cmake
self._cmake = CMake(self)
self._cmake.configure(source_folder=".")
return self._cmake
def build(self):
cmake = self._configure_cmake()
cmake.build()
cmake.install()
def package(self):
cmake = self._configure_cmake()
cmake.install()
tools.rmdir(os.path.join(self.package_folder, "lib", "cmake"))
tools.rmdir(os.path.join(self.package_folder, "lib", "pkgconfig"))
tools.rmdir(os.path.join(self.package_folder, "share"))
def package_info(self):
self.cpp_info.names["cmake_find_package"] = "base"
self.cpp_info.names["cmake_find_package_multi"] = "base"
self.cpp_info.names["pkg_config"] = "base"
which is next to my main CMakeLists.txt file. The CMake project builds without problems and also has a proper install target which installs everything properly: bin,lib,include,share. In CMake I use the conan-cmake module with basically something like this.
When I run
conan create -s build_type=Release . demo/testing
I get the following weird error:
...
Requirements
base-library/1.0.0#demo/testing from local cache - Cache
fmt/8.0.1 from 'conancenter' - Cache
Packages
base-library/1.0.0#demo/testing:4f2b14d304ab8e4391d162a6eb44110cc27a3faa - Build
fmt/8.0.1:d4e9c4f02b4f03edf5a640dcd22779727d782e79 - Cache
Installing (downloading, building) binaries...
fmt/8.0.1: Already installed!
base-library/1.0.0#demo/testing: WARN: Build folder is dirty, removing it: /home/developer/.conan/data/base-library/1.0.0/demo/testing/build/4f2b14d304ab8e4391d162a6eb44110cc27a3faa
base-library/1.0.0#demo/testing: Configuring sources in /home/developer/.conan/data/base-library/1.0.0/demo/testing/source
base-library/1.0.0#demo/testing: Copying sources to build folder
base-library/1.0.0#demo/testing: Building your package in /home/developer/.conan/data/base-library/1.0.0/demo/testing/build/4f2b14d304ab8e4391d162a6eb44110cc27a3faa
base-library/1.0.0#demo/testing: Generator cmake_find_package created Findfmt.cmake
base-library/1.0.0#demo/testing: Generator cmake_find_package_multi created fmt-config-version.cmake
base-library/1.0.0#demo/testing: Generator cmake_find_package_multi created fmt-config.cmake
base-library/1.0.0#demo/testing: Generator cmake_find_package_multi created fmtTargets.cmake
base-library/1.0.0#demo/testing: Generator cmake_find_package_multi created fmtTarget-release.cmake
base-library/1.0.0#demo/testing: Aggregating env generators
base-library/1.0.0#demo/testing: Calling build()
base-library/1.0.0#demo/testing:
base-library/1.0.0#demo/testing: ERROR: Package '4f2b14d304ab8e4391d162a6eb44110cc27a3faa' build failed
base-library/1.0.0#demo/testing: WARN: Build folder /home/developer/.conan/data/base-library/1.0.0/demo/testing/build/4f2b14d304ab8e4391d162a6eb44110cc27a3faa
ERROR: base-library/1.0.0#demo/testing: Error in build() method, line 74
cmake = self._configure_cmake()
while calling '_configure_cmake', line 65
self._cmake = CMake(self)
ConanException: The file /home/developer/.conan/data/base-library/1.0.0/demo/testing/build/4f2b14d304ab8e4391d162a6eb44110cc27a3faa/conanbuild.conf does not exist. Please, make sure that it was not generated in another folder.
What is the problem here and how can I resolve this? I could not find anything related to this?

Answer 1

from conans import ConanFile, CMake
...
def build(self):
cmake = CMake(self)
cmake.configure()
cmake.build()
...

Answer 2

I had the same problem and finally found the issue:
The CMake you are importing is the one working with the CMakeToolchain which are both part of the conan.tools.cmake module.
The one that is described in the usage of cmake_find_package[ref] is the one in conans module
So replacing:
from conans import ConanFile, tools
from conan.tools.cmake import CMake, CMakeToolchain
by
from conans import ConanFile, tools, CMake
from conan.tools.cmake import CMakeToolchain
should fix your problem