diff -r f2f2b81079a5 -r c34106244a54 src/StreamletAttributeFinder.h
--- a/src/StreamletAttributeFinder.h	Sat Apr 23 19:08:11 2022 +0200
+++ b/src/StreamletAttributeFinder.h	Fri May 13 21:35:30 2022 +0200
@@ -145,7 +145,11 @@
 					subProcess->write({StreamletMsg::RELATION_START, relationName});
 					subProcess->write({StreamletMsg::INPUT_ATTRIBUTE_METADATA, L"path", L"string"});
 					for (string_t alias : field.getAliases()) subProcess->write({StreamletMsg::OUTPUT_ATTRIBUTE_ALIAS, alias});
-					for (int i = 0; i < field.options.size();) subProcess->write({StreamletMsg::OPTION, field.options[i++], field.options[i++]});
+					for (int i = 0; i < field.options.size();) {
+						auto code = field.options[i++];
+						auto param = field.options[i++];
+						subProcess->write({StreamletMsg::OPTION, code, param});
+					}
 					subProcess->write({StreamletMsg::WAITING_FOR_OUTPUT_ATTRIBUTES_METADATA});
 
 					vector<AttributeMetadata> metadata;