CMake is not found when installing in the editable mode on Windows

[IvanaGyro]

It seems that py-build-cmake find proper cmake or vs build tool terminal when building normally. But the same mechanism is not implemented in build hook. Here is my editable section in pyproject.toml

[tool.py-build-cmake.editable]
mode = "symlink"
build_hook = true

[tttapa]

Are you using build isolation by any chance?
The build_hook option requires Pip's --no-build-isolation flag: if you want to be able to re-build the package when importing it, all build requirements need to be installed in your environment. With Pip's default build isolation, the build requirements are installed in a temporary environment that is removed after the initial build, so trying to re-build the project without this temporary environment is bound to fail.

See https://tttapa.github.io/py-build-cmake/usage/editable-install.html#build-hooks for details.

[IvanaGyro]

I am not sure if we are talking about the same thing, so I want to explain clearer.

On Windows, cmake and C/C++ compiler (MSVC) are only available in the MSVC build tool terminal. The default terminal does not contain the path of cmake in the PATH environment variable. As a result, cmake does not exist by default. However, pip install . can find cmake properly. I guess there is a mechanism to find the cmake and C/C++ beyond finding then in the PATH environment variable.

In contrast, pip install -e . and pip install -e . --no-build-isolation fail to find cmake properly. cmake is not a Python package, so I think the flag --no-build-isolation doesn't affect if the build system can find cmake or not.

I did these steps in the virtual environment:

1. pip install py-build-cmake
2. pip install -e . --no-build-isolation

and got this error:

  × Failed to build `project_name @ file:///project`      
  ├─▶ The build backend returned an error
  ╰─▶ Call to `py_build_cmake.build.build_editable` failed (exit code: 1)

      [stderr]
      ERROR:py_build_cmake.common:Uncaught exception:
      Traceback (most recent call last):
        File
      "project\.venv\Lib\site-packages\py_build_cmake\build.py",
      line 114, in build_editable
          return self.build_wheel_in_dir(
                 ^^^^^^^^^^^^^^^^^^^^^^^^
        File
      "project\.venv\Lib\site-packages\py_build_cmake\build.py",
      line 277, in build_wheel_in_dir
          cmaker.configure()
        File
      "project\.venv\Lib\site-packages\py_build_cmake\commands\cmake.py",
      line 413, in configure
          self.run(cmd, cwd=cwd, check=True, env=env)
        File
      "project\.venv\Lib\site-packages\py_build_cmake\commands\cmake.py",
      line 126, in run
          return self.runner.run(*args, **kwargs)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File
      "project\.venv\Lib\site-packages\py_build_cmake\commands\cmd_runner.py",
      line 35, in run
          return sp_run(*args, **kwargs)  # noqa: PLW1510
                 ^^^^^^^^^^^^^^^^^^^^^^^
        File "C:\Users\Ivana\.pyenv\pyenv-win\versions\3.12.0b4\Lib\subprocess.py", line 548, in run  
          with Popen(*popenargs, **kwargs) as process:
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "C:\Users\Ivana\.pyenv\pyenv-win\versions\3.12.0b4\Lib\subprocess.py", line 1026, in     
      __init__
          self._execute_child(args, executable, preexec_fn, close_fds,
        File "C:\Users\Ivana\.pyenv\pyenv-win\versions\3.12.0b4\Lib\subprocess.py", line 1538, in     
      _execute_child
          hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      FileNotFoundError: [WinError 2] 系統找不到指定的檔案。
      Traceback (most recent call last):
        File
      "project\.venv\Lib\site-packages\py_build_cmake\build.py",
      line 114, in build_editable
          return self.build_wheel_in_dir(
                 ^^^^^^^^^^^^^^^^^^^^^^^^
        File
      "project\.venv\Lib\site-packages\py_build_cmake\build.py",
      line 277, in build_wheel_in_dir
          cmaker.configure()
        File
      "project\.venv\Lib\site-packages\py_build_cmake\commands\cmake.py",
      line 413, in configure
          self.run(cmd, cwd=cwd, check=True, env=env)
        File
      "project\.venv\Lib\site-packages\py_build_cmake\commands\cmake.py",
      line 126, in run
          return self.runner.run(*args, **kwargs)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File
      "project\.venv\Lib\site-packages\py_build_cmake\commands\cmd_runner.py",
      line 35, in run
          return sp_run(*args, **kwargs)  # noqa: PLW1510
                 ^^^^^^^^^^^^^^^^^^^^^^^
        File "C:\Users\Ivana\.pyenv\pyenv-win\versions\3.12.0b4\Lib\subprocess.py", line 548, in run  
          with Popen(*popenargs, **kwargs) as process:
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "C:\Users\Ivana\.pyenv\pyenv-win\versions\3.12.0b4\Lib\subprocess.py", line 1026, in     
      __init__
          self._execute_child(args, executable, preexec_fn, close_fds,
        File "C:\Users\Ivana\.pyenv\pyenv-win\versions\3.12.0b4\Lib\subprocess.py", line 1538, in     
      _execute_child
          hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      FileNotFoundError: [WinError 2] 系統找不到指定的檔案。

      The above exception was the direct cause of the following exception:

      Traceback (most recent call last):
        File "<string>", line 11, in <module>
        File
      "project\.venv\Lib\site-packages\py_build_cmake\build.py",
      line 118, in build_editable
          format_and_rethrow_exception(e)
        File
      "project\.venv\Lib\site-packages\py_build_cmake\common\__init__.py",
      line 250, in format_and_rethrow_exception
          raise FormattedErrorMessage(msg) from e
      py_build_cmake.common.FormattedErrorMessage:

        ❌ Uncaught exception: FileNotFoundError

                [WinError 2] 系統找不到指定的檔案。

           Please notify the developers: https://github.com/tttapa/py-build-cmake/issues


      hint: This usually indicates a problem with the package or the build environment.
  

[tttapa]

I see what you mean now. The current behavior is as follows:

1. If CMake is available in the path, and its version is at least as new as the specified cmake.minimum_version, py-build-cmake uses that CMake binary.
2. Otherwise, CMake is added to the build requirements, and Pip will install https://pypi.org/project/cmake/ in the build environment for you.

If you use --no-build-isolation, then Pip does not check or install any build requirements, so CMake is not available, and py-build-cmake fails.
If CMake is available in the PATH during the installation, but not while executing the build hook, then the build will also fail, as you've noticed.

There are several possible solutions:

1. As a user, make sure that CMake is available in your PATH, either by having it installed globally on your system, or by installing it into your Python environment using pip install cmake. This is the easiest approach, and this exactly matches the workflow of any other build-time requirements you have (e.g. pybind11). You can pass the --no-build-isolation --check-build-dependencies flags to Pip when doing an editable install to make sure that everything is installed.
2. Treat CMake as special, and hard-code the full path in the installed build hook. This is more brittle, because if the path becomes unavailable for some reason, the build hook will be broken.
3. Add a py-build-cmake option to set the full CMake path (which will also be included in the build hook).

Either way, the error messages you're seeing should definitely be improved.

[IvanaGyro]

There are several possible solutions:...

These solutions are good. However, on Windows, not only the path of CMake is not include in the PATH environment variable but also the path of the compilers installed by the VS build tool, except users open their terminal or editor (like VS Code) from the build tool's developer prompt terminal. This means the build process will still fail even if the path of CMake is manually provided.

It seems that pip install can find CMake and the compilers which are not included in the PATH environment variable but are installed with the Microsoft's build tools. Is it possible also include the same method in py-build-cmake while executing the build hook?