use skopeo

.gitlab-ci.yml

 docker-image:
   stage: build
   image: nixpkgs/nix
-  before_script:
-    - nix run -f channel:nixos-unstable podman -c podman login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
   script:
-    - nix-build docker.nix
-    - nix run -f channel:nixos-unstable podman -c sh -c 'podman load < result'
-    - nix run -f channel:nixos-unstable podman -c podman tag jupyter-image:latest "$CI_REGISTRY_IMAGE:$CI_COMMIT_SHA"
-    - nix run -f channel:nixos-unstable podman -c podman tag jupyter-image:latest "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
-    - nix run -f channel:nixos-unstable podman -c podman push "$CI_REGISTRY_IMAGE:$CI_COMMIT_SHA"
-    - nix run -f channel:nixos-unstable podman -c podman push "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
+    - nix-build docker.nix -o image.tar.gz
+    - |
+      nix run -f channel:nixos-unstable skopeo -c skopeo \
+        --insecure-policy \
+        copy \
+        --dest-creds $CI_REGISTRY_USER:$CI_REGISTRY_PASSWORD \
+        docker-archive:image.tar.gz \
+        docker://$CI_REGISTRY_IMAGE:$CI_COMMIT_SHA

docker.nix

 let
   jupyter = import (builtins.fetchGit {
     url = https://github.com/tweag/jupyterWith;
-    rev = "";
+    rev = "35eb565c6d00f3c61ef5e74e7e41870cfa3926f7";
   }) {};
 
   iHaskell = jupyter.kernels.iHaskellWith {