nix: nom nom 😋

config/nix/build-pindakaas-image.sh

@@ -2,19 +2,22 @@
 
 # Build a disk image for testing on pindakaas via sd card
 
+if ! command -v nom-build
+then
+    exec nix-shell -p nix-output-monitor --run $0
+fi
+
 export NIXPKGS_ALLOW_UNFREE=1
 extra=""
 if [ "$(uname -m)" != "aarch64" ]
 then
-    # If we have binfmt QEMU (https://nixos.wiki/wiki/NixOS_on_ARM#Compiling_through_binfmt_QEMU),
-    # we can pretend we're aarch64.
-    if [ -f /proc/sys/fs/binfmt_misc/qemu-aarch64 ]
+    if [ ! -f /proc/sys/fs/binfmt_misc/qemu-aarch64 ]
     then
+        echo "Use binfmt QEMU!"
+        echo "https://nixos.wiki/wiki/NixOS_on_ARM#Compiling_through_binfmt_QEMU"
+        exit 1
+    fi
     extra="--argstr system aarch64-linux"
-    # Otherwise, use cross-compilation...
-    # theorically faster but doesn't use the cache and never got it to build a full customized image
-    else
-        extra="--argstr nixpkgs.crossSystem.system aarch64-linux"
 fi
-fi
-nix-build '<nixpkgs/nixos>' -A config.system.build.sdImage -I nixos-config=./pindakaas.nix $extra --show-trace
+nom-build '<nixpkgs/nixos>' -A config.system.build.sdImage \
+    -I nixos-config=./pindakaas.nix $extra --show-trace

config/nix/build-vm.sh

@@ -5,6 +5,11 @@
 # For x86_64 hosts: use curacao config
 # For aarch64 hosts: use pindakaas config
 
+if ! command -v nom-build
+then
+    exec nix-shell -p nix-output-monitor --run $0
+fi
+
 export NIXPKGS_ALLOW_UNFREE=1
 if [ "$(uname -m)" == "x86_64" ]
 then
@@ -13,6 +18,5 @@ elif [ "$(uname -m)" == "aarch64" ]
 then
     config=./pindakaas.nix
 fi
-nix-build '<nixpkgs/nixos>' -A vm \
--I nixpkgs=channel:nixos-23.05 \
+nom-build '<nixpkgs/nixos>' -A vm \
     -I nixos-config=${config}