The problem seems to be related to permissions. In order to create a target
folder, I have to use 'sudo" to gain the required root privileges, but if I
start httrack from the console with "sudo httrack" I get a dire warning.

Then I tried a workaround. I copied the penultimate line in the httrack output
and pasted it into the command line, but preceded with sudo. That started the
download just fine, but then I noticed that httrack was copying all of all the
sites to which my target site links. I appended "-%e1" to the list of options,
and all went well for a while until httrack started copying all of a
commercial site.