Check binfmt_misc module is loaded

Give a friendly error message early.

Dockerfile

@@ -6,7 +6,7 @@ RUN apt-get -y update && \
     apt-get -y install \
         git vim parted \
         quilt realpath qemu-user-static debootstrap zerofree pxz zip dosfstools \
-        bsdtar libcap2-bin rsync grep udev xz-utils curl xxd file \
+        bsdtar libcap2-bin rsync grep udev xz-utils curl xxd file kmod\
     && rm -rf /var/lib/apt/lists/*
 
 COPY . /pi-gen/

depends

@@ -15,3 +15,4 @@ curl
 xxd
 file
 git
+lsmod:kmod

scripts/dependencies_check

@@ -27,4 +27,13 @@ dependencies_check()
 		echo "$missing"
 		false
 	fi
+
+
+	if ! lsmod | grep binfmt_misc >/dev/null
+	then
+		echo "Module binfmt_misc not loaded in host"
+		echo "Please run:"
+		echo "  sudo modprobe binfmt_misc"
+		exit 1
+	fi
 }