fix: don't try to replace a mount point

binhost.sh

@@ -66,7 +66,7 @@ VOLUMES=(
     -v distfiles:/var/cache/distfiles
     -v binpkgs:/var/cache/binpkgs
     -v "$CTX/etc/portage/make.conf:/etc/portage/make.conf"
-    -v "$CTX/var/lib/portage/world:/var/lib/portage/world"
+    -v "$CTX/var/lib/portage:/tmp/incoming_world:ro"
 )
 
 # add config dirs to volumes
@@ -84,6 +84,8 @@ podman run --rm -i \
 set -e
 source /etc/profile
 
+cp /tmp/incoming_world/world /var/lib/portage/world
+
 echo "> Syncing tree..."
 emerge-webrsync -q