debug hook callback is not called from __gc metamethod

[Paul K <paul@...>]

Hi All,

I'm running the following script and no debug hook events are
generated from the __gc metamethod (even though the lines do get
executed):

do
  local a=setmetatable({},{__gc=function()
    print("GC") -- 3
    end})
end
debug.sethook(function(...) print(...) end,"clr")
collectgarbage("collect") -- 7
print("done") -- 8

The output using Lua 5.3:

return    nil
line    7
call    nil
GC
return    nil
line    8
call    nil
call    nil
return    nil
Done
return    nil
return    nil
return    nil

"GC" is printed, but no line event is generated. I get the same result
with Lua 5.2. Is this by design?

Paul.