Ports: Support multiple port directories

This allows Ports unfit for the main repository to be put elsewhere.

Ports/.hosted_defs.sh

@@ -56,3 +56,4 @@ export PKG_CONFIG_SYSROOT_DIR="${SERENITY_BUILD_DIR}/Root"
 export PKG_CONFIG_LIBDIR="${PKG_CONFIG_SYSROOT_DIR}/usr/local/lib/pkgconfig"
 
 export SERENITY_INSTALL_ROOT="${SERENITY_BUILD_DIR}/Root"
+export SERENITY_PORT_DIRS="${SERENITY_PORT_DIRS:+${SERENITY_PORT_DIRS}:}${SERENITY_SOURCE_DIR}/Ports"

Ports/.port_include.sh

@@ -528,7 +528,17 @@ package_install_state() {
 installdepends() {
     for depend in "${depends[@]}"; do
         if [ -z "$(package_install_state $depend)" ]; then
-            (cd "${PORT_META_DIR}/../$depend" && ./package.sh --auto)
+            # Split colon seperated string into a list
+            IFS=':' read -ra port_directories <<< "$SERENITY_PORT_DIRS"
+            for port_dir in "${port_directories[@]}"; do
+                if [ -d "${port_dir}/$depend" ]; then
+                    (cd "${port_dir}/$depend" && ./package.sh --auto)
+                    return
+                fi
+            done
+
+            >&2 echo "Error: Dependency $depend could not be found."
+            exit 1
         fi
     done
 }