''What'', for that matter, is The Bug Directory?
Is it the [Sourceforge] "Bugs browser" specific to 
[Tcl]
[http://sourceforge.net/tracker/?atid=110894&group_id=10894&func=browse]
?
If so, then for example, to read up on Bug 219191, means to
retrieve
http://sourceforge.net/tracker/index.php?func=detail&aid=219191&group_id=10894&atid=110894 .
But why are some Bugs in the range above 600000?
Where are the reports for [Tk], [tcllib], and so on?






If one just wants results, rather than the technical details, [Don Porter]'s
"[SourceForge bug-reporting interface]" 
is convenient.
Also pertinent:
"[How do I report a bug in Tcl, Tk, ...]".