chore(gitlab-ci): ...

.gitlab-ci.yml

@@ -6,7 +6,10 @@ workflow:
 
 default:
   image:
-    name: nixos/nix:2.3.12
+    name: nixpkgs/nix-flakes:nixos-21.05
+
+variables:
+  NIX_PATH: "nixpkgs=http://nixos.org/channels/nixos-21.05/nixexprs.tar.xz"
   
 stages:
   - setup
@@ -16,9 +19,7 @@ node dependencies:
   script:
     - nix build -o node-dependencies .#uniworxNodeDependencies
   before_script:
-    - install -m 0644 .gitlab-ci/nix-bootstrap.conf /etc/nix/nix.conf
-    - nix-channel --update
-    - nix-env -f '<nixpkgs>' -riA envsubst nixUnstable git coreutils
+    - nix-env -f '<nixpkgs>' -riA envsubst
     - envsubst -i .gitlab-ci/nix.conf -o /etc/nix/nix.conf
     - git config --global init.defaultBranch master
     - install -v -m 0700 -d ~/.ssh

.gitlab-ci/nix-bootstrap.conf

@@ -1,5 +1,4 @@
 sandbox = true
-experimental-features = nix-command flakes ca-references
 substituters = https://hydra.iohk.io https://cache.nixos.org/
 trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
 require-sigs = true