This works fine on Ubuntu (with a different keyring path). Here's the command
line and output (using Gpg4win 2.2.0):
PS C:\Users\Bruce\Downloads> gpg --keyring=./debian-keyring.gpg --list-key
BACE15D2A57498FF
gpg: keyblock resource `C:/Users/Bruce/AppData/Roaming/gnupg/./debian-
keyring.gpg': No such file or directory
gpg: error reading key: No public key