Can't connect using SSH key without storing passphrase in plaintext

[M-Pixel]

With or without agent, config that contains "privateKeyPath": "/some/key" and "passphrase": null, output reads the following then hangs indefinitely:

[sync-helper] prepareSync
[sync-helper] connect

The status bar reads,

Ftp-sync: sync prepare in progress... connecting...

[jakeparis]

Are you using a non-rsa key? Rsa seems to be a requirement: #28 (comment)

[M-Pixel]

This was with an RSA key, but one which is passphrase-protected. I hoped that by specifying "passphrase": null, I would be prompted for the passphrase.

[tominal]

afaik passphrase prompting isn't in this extension