I am having trouble exporting secret keys programmatically. I am using GPGME via the Rust bindings but as you can see in the attached link it seems that the issue comes from the library itself. The passphrase callback is not used when exporting secret keys. I am not sure if this is expected or not.
---
In createkey_start for example:
```
if (ctx->passphrase_cb)
{
err = _gpgme_engine_set_command_handler
(ctx->engine, _gpgme_passphrase_command_handler, ctx);
if (err)
return err;
}
```