msgutil.js prints the contents of the script rather than it's output

If I run, for example, ./jsexec ./msgutil.js -hdrs mail (Ubuntu Linux/SBBS 18c) or .\jsexec.exe .\msgutil.js -hdrs mail (Windows 10/SBBS 19c (bleeding edge overnight build 27 June 2021) I get the same result, that is that the headers of the Netmails are printed correctly for all fields up to can_read = true. The next field is get_rfc822_header = but after the = sign, instead of printing the rfc822 header, the contents of load/822header.js is printed out in it's entirety for each record. Using the param -index or -export work as expected.