FetchWorkspaceError: rust-analyzer failed to load workspace: "cargo" "--version" failed: The directory name is invalid. (os error 267)

Currently when I try to run rust-analyzer in vscode on Windows I always get the error
FetchWorkspaceError: rust-analyzer failed to load workspace: "cargo" "--version" failed: The directory name is invalid. (os error 267)
This happens regardless of which projects are in my vscode workspace. It even happens when the vscode workspace is empty!

I am currently using rust-analyzer nighlty
rust-analyzer version: 0.4.1488-standalone (bc78ebd9d 2023-04-23)

I tried with both stable and nightly rust, in case that made any difference - it does not.
rustc 1.69.0 (84c898d65 2023-04-16)
rustc 1.71.0-nightly (8bdcc62cb 2023-04-20)

I find the error message less than helpful. It would be a really good idea to include which directory name is supposedly invalid.

When I have a valid rust project in my vscode workspace, cargo check runs just fine, so something else must be the true problem.

The issue names no repository files or tests. Reproduce the failure in VS Code on Windows with an empty workspace, then trace the "cargo" "--version" invocation and identify how its working directory is selected. Done means the error reports which directory is invalid while preserving the existing failure behavior.