I needed to have a look at package.tcl (22.214.171.124) in
order to understand the workings of pkg_mkIndex.
Now, on line 253 the 'catch' of an 'eval' of a slave
interpreter is started. If the 'catch' triggers (lines
356-359) the slave is not deleted, whereas if
everything is well (lines 361-383) it is.
To me this looks like a leak.