Unable to find toolchain on Windows

[HarukaMa]

I got this after installing Swift with the official Swift installer:

I can confirm the file expected by the plugin is there:

When I use an invalid path, I can see in the log that the plugin reports missing sourcekit-lsp.exe file, but when using the correct path like in the screenshot above, there is zero log indicating why it doesn't work.

^{I understand the closed-source rationale, but I would be able to see what exactly happened if this was open source}