Extending home-gpg-agent-service-type from a service-type doesn't do anything?

Extending home-gpg-agent-service-type from a service-type doesn't do anything?

[Simen Endsjø]

I'm probably doing something wrong, but I'm having problems using
`home-gpg-agent-service-type' from a service. It works fine inside an
`home-environment', but not within a service type.

So this works fine:
,----
| (home-environment
|   (services
|    (list
|     (service home-gpg-agent-service-type
|              (home-gpg-agent-configuration
|               (pinentry-program
|                (file-append sijo-pinentry "/bin/sijo-pinentry"))
|               (extra-content "allow-loopback-pinentry"))))))
| 
`----

But when I move this into a new service, it doesn't seem to do anything,
and only the default configuration is used.

,----
| (home-environment
|   (services
|    (list
|     (service sijo-gpg-service-type))))
| 
| (define-public sijo-gpg-service-type
|   (service-type
|    (name 'sijo-gpg-service)
|    (extensions
|     (list
|      (service-extension home-profile-service-type
|                         (lambda (config)
|                           (list sijo-pinentry)))
|      ;; This doesn't actually see mto do anything
|      (service-extension home-gpg-agent-service-type
|                         (lambda (config)
|                           (home-gpg-agent-configuration
|                            (pinentry-program
|                             (file-append sijo-pinentry "/bin/sijo-pinentry"))
|                            (extra-content "allow-loopback-pinentry"))))))
|    (default-value #f)
|    (description "")))
`----