Hi Tobias,

Yes I am aware that it's more complicated than the initial question, I'm fine with adding all the dependencies as inputs.

I was simply asking the correct way to handle optional inputs.

> Does that not work?

Yes it would absolutely work, I have tested as such in depth on multiple guix systems.

> For things like templates {native-,}search-paths can be a
solution, depending on how yadm (or its templating library)
searches for these.

Yes I still have further testing with regards to templates as I don't personally use them.

Thanks you for your input Tobias
On 6 Feb 2021, at 11:37, Tobias Geerinckx-Rice <me@tobias.gr> wrote:
Ellis,

Ellis Kenyő via Guix-patches via 写道：
 I was asking if there was a simple way to handle optional 
 inputs.

While this is an oxymoron for the reasons pointed out by Leo, 
there is _nothing_ wrong with simply leaving some variables at 
their default e.g.

  GPG_PROGRAM="gpg"

and letting yadm look them up at run time in its $PATH.

Does that not work?

For things like templates {native-,}search-paths can be a 
solution, depending on how yadm (or its templating library) 
searches for these.

Kind regards,

T G-R