[DDW-1189] Fix Buildkite a bit more

Author: michalrus

.buildkite/pipeline.yml

@@ -9,27 +9,27 @@ steps:
     key: 'trigger-aarch64-darwin'
 
   - label: 'daedalus-x86_64-darwin'
-    command: 'scripts/with-nix-2.5.sh scripts/build-installer-unix.sh --build-id $BUILDKITE_BUILD_NUMBER'
+    command: 'scripts/with-nix-unstable.sh scripts/build-installer-unix.sh --build-id $BUILDKITE_BUILD_NUMBER'
     depends_on: 'trigger-x86_64-darwin'
     agents:
       queue: lace
       system: x86_64-darwin
 
   - label: 'daedalus-aarch64-darwin'
-    command: 'scripts/with-nix-2.5.sh scripts/build-installer-unix.sh --build-id $BUILDKITE_BUILD_NUMBER'
+    command: 'scripts/with-nix-unstable.sh scripts/build-installer-unix.sh --build-id $BUILDKITE_BUILD_NUMBER'
     depends_on: 'trigger-aarch64-darwin'
     agents:
       queue: lace
       system: aarch64-darwin
 
   - label: 'daedalus-x86_64-linux-nix'
-    command: 'scripts/with-nix-2.5.sh scripts/build-installer-nix.sh $BUILDKITE_BUILD_NUMBER'
+    command: 'scripts/with-nix-unstable.sh scripts/build-installer-nix.sh $BUILDKITE_BUILD_NUMBER'
     agents:
       queue: lace
       system: x86_64-linux
 
   - label: 'daedalus-x86_64-windows-nix'
-    command: 'scripts/with-nix-2.5.sh scripts/build-cross-windows.sh $BUILDKITE_BUILD_NUMBER'
+    command: 'scripts/with-nix-unstable.sh scripts/build-cross-windows.sh $BUILDKITE_BUILD_NUMBER'
     agents:
       queue: lace
       system: x86_64-linux

scripts/with-nix-2.5.sh renamed to scripts/with-nix-unstable.sh

@@ -8,8 +8,8 @@ fi
 
 echo "~~~ Obtaining ‘pkgs.nixUnstable’"
 
-myDir=$(dirname "$0")
-nixUnstable=$(nix-build "$myDir"/../default.nix -A pkgs.nixUnstable)
+# fe2ecaf706a5907b5e54d979fbde4924d84b65fc is nixos-unstable on 2023-04-13
+nixUnstable=$(nix-build https://github.com/NixOS/nixpkgs/archive/fe2ecaf706a5907b5e54d979fbde4924d84b65fc.tar.gz -A pkgs.nixUnstable)
 
 PATH="$nixUnstable/bin:$PATH"