"pyoxidizer run" seems to fail if there are spaces in the build path (Windows)

Completely rewriting this issue because the original problem was dumb (just didn't have Rust installed -- though there were two issues there: the installer didn't put pyoxidizer on user or system path, and after I did that manually, it wasn't clear that the lack of Rust was the problem).

After fixing the above, I discovered that it still wouldn't build, with the relevant output at the bottom of this message. I moved the project to another folder with no spaces in the path and it worked great. Seems like it needs some quotes somewhere?

> building with Rust 1.51.0
> error: failed to run `rustc` to learn about target-specific information
>
> Caused by:
> process didn't exit successfully: `rustc - --crate-name ___ --print=file-names -LC:\Users\myusername\example dir name\example name\repo\test-suite\pyapp\.\build\python_distributions\python.ebf4acc5dff2\python\install --target x86_64-pc-windows-msvc --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=cfg` (exit code: 1)
> --- stderr
> error: multiple input filenames provided (first two filenames are `-` and `dir`)
>
> error[PYOXIDIZER_PYTHON_EXECUTABLE]: adding PythonExecutable to FileManifest
>
> Caused by:
> 0: building Python executable
> 1: building executable with Rust project
> 2: command ["C:\\Users\\myusername\\.cargo\\bin\\cargo.EXE", "build", "--target", "x86_64-pc-windows-msvc", "--target-dir", "C:\\Users\\myusername\\AppData\\Local\\Temp\\pyoxidizerjEnDAe\\build\\target", "--bin", "pyapp", "--no-default-features", "--features", "build-mode-prebuilt-artifacts cpython-link-default"] exited with code 101
> --> .\pyoxidizer.bzl:270:5
> |
> 270 | files.add_python_resource(".", exe)
> | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ to_file_manifest()
>
>
> error: adding PythonExecutable to FileManifest
>
> Caused by:
> 0: building Python executable
> 1: building executable with Rust project
> 2: command ["C:\\Users\\myusername\\.cargo\\bin\\cargo.EXE", "build", "--target", "x86_64-pc-windows-msvc", "--target-dir", "C:\\Users\\myusername\\AppData\\Local\\Temp\\pyoxidizerjEnDAe\\build\\target", "--bin", "pyapp", "--no-default-features", "--features", "build-mode-prebuilt-artifacts cpython-link-default"] exited with code 101

Reproduce the Windows failure using a project path containing spaces and inspect the command reported by `pyoxidizer run`, especially the `rustc` invocation and the reference to `.\pyoxidizer.bzl:270`. Trace how that command is assembled, then verify that the build completes successfully from a spaced path without splitting path arguments.

Written by the indexing model from the issue text.