Error building Nixos with Antigen

Hi,

I am rebuilding my image and I am getting the following errors:

building ‘/nix/store/l8gcy64wbfn00glkhl7i79yr7msck3yl-antigen-1359b99.drv’…
exporting GitHub - zsh-users/antigen: The plugin manager for zsh. (rev 1359b9966689e5afb666c2c31f5ca177006ce710) into /nix/store/kxgidpjk31ydfrj93b9nrbfqkdcnjdsh-antigen-1359b99
Initialized empty Git repository in /nix/store/kxgidpjk31ydfrj93b9nrbfqkdcnjdsh-antigen-1359b99/.git/
fatal: unable to access ‘GitHub - zsh-users/antigen: The plugin manager for zsh.’: SSL certificate problem: self signed certificate
fatal: unable to access ‘GitHub - zsh-users/antigen: The plugin manager for zsh.’: SSL certificate problem: self signed certificate

I was able to build the image before but now it just failed with the errors above. Is there a way to get around this issue? Thank you for your help.