skip iso/qcow image generation for AWS-only arrow host

docs/CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 2026-10-17: fix flake check for AWS-only arrow
+
+- `nix flake check` (run by the weekly Update Flake workflow) failed evaluating `packages.x86_64-linux.arrow-iso`: arrow now imports `amazon-image.nix` directly, which conflicts with the `iso` and `qcow-efi` generator formats (`boot.loader.timeout` 1 vs 10, and similar).
+- `flake.nix` now has an `awsOnlyHosts = [ "arrow" ]` list; those hosts only get the `-aws` image. `arrow-iso` and `arrow-qcow` are no longer exported.
+
 ## 2026-10-15: post-TUI lag — re-investigation, timestamped recorder
 
 - **Status: root cause still unproven.** Not reproducible in fresh shells: a PTY harness (with and without a real zellij 0.45.1 session, fish 4.9.3, the real config and a copy of the real history) showed no echo-latency change after hx (with nixd/marksman/rumdl running), jjui, yazi, vim, less, lazygit or Claude Code, nor with huge history autosuggestions or concurrent history writers.

flake.nix

@@ -183,27 +183,35 @@
         root = import ./hosts/x86_64-linux/swan/root.nix;
       };
 
+      awsOnlyHosts = [ "arrow" ];
+
       generators = builtins.mapAttrs (
         # x86_64-linux = { arrow = ...; swan = ...; }
         system: hosts:
-        (lib.concatMapAttrs (name: module: {
-          "${name}-aws" = lib.generateImage {
-            inherit system module;
-            format = "amazon";
-            specialArgs = { inherit hostnames; };
-          };
-          "${name}-iso" = lib.generateImage {
-            inherit system module;
-            format = "iso";
-            specialArgs = { inherit hostnames; };
-          };
-          "${name}-qcow" = lib.generateImage {
-            inherit system module;
-            format = "qcow-efi";
-            specialArgs = { inherit hostnames; };
-            # extraModules = [ "${nixpkgs}/nixos/modules/virtualisation/oci-image.nix" ];
-          };
-        }) hosts)
+        (lib.concatMapAttrs (
+          name: module:
+          {
+            "${name}-aws" = lib.generateImage {
+              inherit system module;
+              format = "amazon";
+              specialArgs = { inherit hostnames; };
+            };
+          }
+          # Hosts that import amazon-image.nix directly conflict with other formats
+          // lib.optionalAttrs (!builtins.elem name awsOnlyHosts) {
+            "${name}-iso" = lib.generateImage {
+              inherit system module;
+              format = "iso";
+              specialArgs = { inherit hostnames; };
+            };
+            "${name}-qcow" = lib.generateImage {
+              inherit system module;
+              format = "qcow-efi";
+              specialArgs = { inherit hostnames; };
+              # extraModules = [ "${nixpkgs}/nixos/modules/virtualisation/oci-image.nix" ];
+            };
+          }
+        ) hosts)
       ) lib.linuxHosts # x86_64-linux = { arrow = ...; swan = ...; }
       ;