Why do not all Lua errors give stack traces?

[infinitywrai]

I have to ask, why are only some Lua errors giving stack traces? Here is an example where I had to insert my own stacktrace into IsValid() to solve a problem: [URL]http://www.facepunch.com/showthread.php?t=1221514&p=38230196#post38230196[/URL]

Here are some errors from my lua_errors_server.txt:

ERROR: Hook 'CheckTimers' Failed: lua/includes/util.lua:184: bad key to string index (number expected, got string) Removing Hook 'CheckTimers'



[ERROR] ...ion 0.95/lua/weapons/gmod_tool/stools/easy_precision.lua:259: 'end' expected (to close 'function' at line 130) near 'else'
  1. unknown - addons/easy precision 0.95/lua/weapons/gmod_tool/stools/easy_precision.lua:0


[ERROR] addons/infbuildrpbenefits/lua/infbuildrp/init.lua:24: attempt to call method 'IsAdmin' (a nil value)
  1. unknown - addons/infbuildrpbenefits/lua/infbuildrp/init.lua:24
   2. unknown - lua/includes/modules/concommand.lua:69

Couldn't include file 'includes\modules\glon.lua' (File not found) (<nowhere>)
Couldn't include file 'includes\modules\glon.lua' (File not found) (<nowhere>)

As you can see the part where CheckTimers failed gives no stack trace, except only one level above. In this case the error cave from IsValid, which is used in so many places it would be difficult to debug it. Also misc errors like couldn't include module should have traces too?

[RP-01]

And in which universe is the stack trace missing? In my universe at least, the stack trace is to 100% complete.

[quote]Also misc errors like couldn't include module should have traces too?[/quote]
What should it trace back to, when the file is just plainly missing? GLON got removed in GMod 13.

[infinitywrai]

I'm sorry but in

ERROR: Hook 'CheckTimers' Failed: lua/includes/util.lua:184: bad key to string index (number expected, got string) 
Removing Hook 'CheckTimers'

The trace only goes up one level. That is not a stack trace.