build using the remote store (but copy explicitly now!)

build.sh

@@ -8,13 +8,20 @@ if test -z "$SYSTEM"; then
   exit 1
 fi
 
-set -x
-# TODO: it'd be really cool to use
 # https://blog.nixbuild.net/posts/2022-03-16-lightning-fast-ci-with-nixbuild-net.html
-# eventually, but for now it's giving me some trouble copying the built closure
-# after the build, so we can't actually do the deploy. It'll probably get stabler
-# in the future, and I should try again then.
-nix --extra-experimental-features "nix-command flakes" \
-    build \
-    --print-build-logs \
-    ".#nixosConfigurations.${SYSTEM}.config.system.build.toplevel"
+set -x
+OUTPUT="$(
+  nix --extra-experimental-features "nix-command flakes" \
+      build \
+      --json \
+      --eval-store auto \
+      --store ssh-ng://eu.nixbuild.net \
+      --print-build-logs \
+      ".#nixosConfigurations.${SYSTEM}.config.system.build.toplevel" 
+)"
+
+OUT="$(jq -r '.[0]'.outputs.out <<< "$OUTPUT")"
+
+nix-copy-closure --from eu.nixbuild.net "$OUT"
+if test -h result; then rm result; fi
+ln -s "$OUT" result