The pkgIndex.tcl file for the Thread and Ttrace
packages creates the commands [::thread_load]
and [::thread_source] inside every interp that
happens to run [::tclPkgUnknown], whether or
not that interp ever actually does a [package require]
on Thread or Ttrace. This is unwelcome pollution.
Bad by any measure. Doubly bad in the global namespace.
This is very easy to fix with the use of the
[::apply] command, so long as a dependence on
Tcl 8.5 is permissible.
If there is movement to better separate the two
packages (see message on TCLCORE), then
the index script may change enough as a result
of that to make the issue go away.