When I try to set the PULUMI_CONFIG_PASSPHRASE I get an error, but setting the PULUMI_CONFIG_PASSPHRASE_FILE works:

$ PULUMI_CONFIG_PASSPHRASE="REDACTED" pulumi stack output url
error: failed to decrypt: incorrect passphrase, please set PULUMI_CONFIG_PASSPHRASE to the correct passphrase or set PULUMI_CONFIG_PASSPHRASE_FILE to a file containing the passphrase