bug#41941: Signing git commits with PGP fails

[Jonathan Brielmaier]

On 19.06.20 03:52, Leo Famulari wrote:
> On Fri, Jun 19, 2020 at 12:35:09AM +0200, Jonathan Brielmaier wrote:
>> I have a strange error/problem with signing git commits with PGP.
>
> The setup can be complicated...
>
>> Following situation
>>
>> `git` is installed via system configuration
>> `git:send-email` via `guix install` into the user profile
>>
>> ~/.gitconfig has
>> ```
>> [commit]
>>   gpgsign = true
>> ```
>
> I also have:
>
> ------
> [gpg]
>         program = gpg
> [user]
>         signingkey = B0515948F1E7D3C1B98038A02646FA30BACA7F08
> ------

Oke, the signingkey parameter is also present in my config.

>> but trying to sign a git commit fails:
>> ```
>> git commit -m "test"
>> error: gpg failed to sign the data
>> fatal: failed to write commit object
>> ```
>
> Do you also have a GPG pinentry program installed? Are you able to sign
> an arbitrary file with GPG, outside of Git? For example:
>
> $ gpg --output test.sig --sign file

I have pinentry installed from the config.scm, but it's still
```
gpg --output test.sig --sign TODO.md
gpg: signing failed: No pinentry
gpg: signing failed: No pinentry
```
Do I need an additional service?