Q: select between multiple signing key

[Hideki Yamane]

Hi,

 I've generated multiple sign subkey but could not select it,
 only last generated one was used.

> $ gpg2 --edit-key henrich at example.jp
> gpg (GnuPG) 2.2.8; Copyright (C) 2018 Free Software Foundation, Inc.
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.
>
> sec  rsa2048/A65B17610C406CE6
>      created: 2018-08-21  expires: never       usage: SC  
>      trust: ultimate      validity: ultimate
> ssb  rsa2048/4B9A876348781F24
>      created: 2018-08-21  expires: never       usage: E   
> ssb  rsa2048/F216455835F7F392
>      created: 2018-08-21  expires: never       usage: S   
> ssb  rsa2048/BD6695496E30735F
>      created: 2018-08-21  expires: never       usage: S   
> [ultimate] (1). Hideki Yamane <henrich at example.jp>

 There are three sign keys (one is Master, other two are subkey).
 Then tried to sign file with Masterkey...

> $ gpg2 --default-key A65B17610C406CE6 --clearsign .bashrc 

 But asked passphrase for BD6695496E30735F, the last generated one.


 My question is
  - Can we have multiple signature subkey on one GPG key?
  - If so, how do select it?
  - If not, why we can do exec addkey?

-- 
Regards,

 Hideki Yamane     henrich @ debian.org/iijmio-mail.jp