Add error for iseqs compiled by prism

ast.c

@@ -253,6 +253,11 @@ ast_s_of(rb_execution_context_t *ec, VALUE module, VALUE body, VALUE keep_script
     if (!iseq) {
         return Qnil;
     }
+
+    if (ISEQ_BODY(iseq)->prism) {
+        rb_raise(rb_eRuntimeError, "cannot get AST for ISEQ compiled by prism");
+    }
+
     lines = ISEQ_BODY(iseq)->variable.script_lines;
 
     VALUE path = rb_iseq_path(iseq);

lib/error_highlight/base.rb

@@ -54,7 +54,16 @@ module ErrorHighlight
 
       return nil unless Thread::Backtrace::Location === loc
 
-      node = RubyVM::AbstractSyntaxTree.of(loc, keep_script_lines: true)
+      node =
+        begin
+          RubyVM::AbstractSyntaxTree.of(loc, keep_script_lines: true)
+        rescue RuntimeError => error
+          # RubyVM::AbstractSyntaxTree.of raises an error with a message that
+          # includes "prism" when the ISEQ was compiled with the prism compiler.
+          # In this case, we'll set the node to `nil`. In the future, we will
+          # reparse with the prism parser and pass the parsed node to Spotter.
+          raise unless error.message.include?("prism")
+        end
 
       Spotter.new(node, **opts).spot