the following code generates IOException:

dir($READONLY_DIR){
stash name: abc, includes:$SOMEFILE
}

running into error:
java.io.IOException: Failed to mkdirs: $READONLY_DIR@tmp/durable-XXXXXXXX

seems stash is trying to create dir with the dir given in context here
there are workaround of this (e.g. write to a different file) but I feel this can be solved by adding a parameter to control where that tmp file is stored.