See Official PlatformIO + Arduino IDE support for the Raspberry Pi Pico is now available! and Upload port required · Issue #2 · platformio/platform-raspberrypi · GitHub.
For the first firmware upload, you need to plug in the Pi with the BOOTSEL button pressed so that it shows up as UF2 drive. Then, use Zadig to change the driver of the RP2040 to WinUSB. Then, use the normal picotool upload – do not use upload_port = E: or a upload_protocol = .. directive in the platformio.ini.
That is indeed a bug (somebody did not escape paths) but not relevant in your case since it’s the wrong upload method altogether.