Add fallback to our mesa package for non-NixOS hosts

flake.nix

@@ -70,6 +70,7 @@
           };
 
           munix = pkgs.callPackage ./packages/munix {
+            mesa = self.packages.${system}.mesa;
             muvm = self.packages.${system}.muvm;
             sidebus-broker = sidebus.packages.${system}.sidebus-broker;
           };

munix

@@ -15,6 +15,10 @@ PIPEWIRE=1
 X11=0
 export TMP=/tmp TMPDIR=/tmp TEMP=/tmp TEMPDIR=/tmp LC_ALL=C
 
+if [ ! -e "$HOST_OPENGL_DRIVER" ]; then
+  HOST_OPENGL_DRIVER="$FALLBACK_OPENGL_DRIVER"
+fi
+
 while [ "$#" -gt 0 ]; do
   case "$1" in
     -u|--uid) MICROVM_UID="$2"; shift 2;;
@@ -58,6 +62,11 @@ if [ "$PASST_PATH" = "" ]; then
   exit 1
 fi
 
+if [ ! -e "$HOST_OPENGL_DRIVER" ]; then
+  echo "munix: host graphics driver not found, provide a --host-opengl-driver" >&2
+  exit 1
+fi
+
 # Resolve symlinks automatically
 MICROVM_CLOSURE=$(realpath "$MICROVM_CLOSURE")
 

packages/munix/default.nix

@@ -1,4 +1,4 @@
-{ writeScriptBin, symlinkJoin, makeWrapper, muvm, passt, bubblewrap, sidebus-broker }:
+{ writeScriptBin, symlinkJoin, makeWrapper, muvm, passt, bubblewrap, sidebus-broker, mesa }:
 
 let
   munixScript = (writeScriptBin "munix" (builtins.readFile ../../munix)).overrideAttrs(old: {
@@ -9,6 +9,6 @@ in symlinkJoin {
   paths = [ munixScript muvm passt bubblewrap sidebus-broker ];
   buildInputs = [ makeWrapper ];
   postBuild = ''
-    wrapProgram $out/bin/munix --prefix PATH : $out/bin
+    wrapProgram $out/bin/munix --prefix PATH : $out/bin --set FALLBACK_OPENGL_DRIVER ${mesa}
   '';
 }