Error running call reference function - lua

I am having an error whilst trying to run a resource on a game server. I believe this line of code in the console is the issue;
Error running call reference function for resource es_extended:
citizen:/scripting/lua/scheduler.lua:351: server/main.lua:237: attempt to
index a nil value (global 'Async')
I have been to line 351 to find this;
error(err)
I then went to line 237 to find this;
Async.parallel(tasks, function(results)
I cannot see for the life of me anything wrong with either lines of code. So any and all advice is greatly recieved.


The global variable Async is a nil value. Hence indexing it like this:
Async.parallel
is not possible. Therefor Lua throws an error.
To fix it, find out why Async is nil and change that, or do not index it.

Related

NeoVim - Check if a Vim function exists from Lua

I plan on using vim-plug with NeoVim. So, my init.lua file will have function calls such as
vim.fn['plug#begin'](vim.fn.stdpath('data') .. '/plugged')
vim.fn['plug#']('hoob3rt/lualine.nvim')
However, I don't want to assume vim-plug is definitely installed. I want my init.lua file to degrade gracefully if vim-plug is not installed, rather than throwing an error
E5113: Error while calling lua chunk: Vim:E117: Unknown function: plug#begin
stack traceback:
[C]: in function 'plug#begin'
/Users/andy/.config/nvim/init.lua:8: in main chunk
How can I check if the vim-plug functions exist before attempting to call them?
I tried print(vim.fn['plug#begin']) but that for some reason prints a non-null value: function: 0x0104ba36f0, even though the function doesn't exist.

I tried print(vim.fn['plug#begin']) but that for some reason prints a non-null value: function: 0x0104ba36f0, even though the function doesn't exist.
Presumably it's returning a function that throws the error you are getting. I would thus recommend using pcall:
local success, error = pcall(vim.fn['plug#begin'], vim.fn.stdpath('data') .. '/plugged')
if not success then --[[fail gracefully]] end
caveat: this will catch any error, so you'll probably want to perform some check like if error:find"Unknown function" then ... end to only catch this specific error.

How to get more information for an error generated in libcontainer/rootfs_linux.go?

Code used from github: https://github.com/opencontainers/runc/blob/master/libcontainer/rootfs_linux.go#L59
This is the if block to debug for our interest....
if err := mountToRootfs(m, config.Rootfs, config.MountLabel, hasCgroupns); err != nil {
return newSystemErrorWithCausef(err, "mounting %q to rootfs at %q", m.Source, m.Destination)
}
Here in the if condition, there is an error generated thru newSystemErrorWithCausef function and which internally uses generic_error.go, fmt.Sprintf to format the error string.
In our integration, only once it hit this if block. And in the process of getting more details, I wanted to troubleshoot and understand why this happened.
As of now tried using fmt.Printf(........) in line 55 and also just before if block of line 59.
And also tried putting above statement in very first line of prepareRootfs function. And then tried newSystemErrorWithCause(err, "some other message") in the first line of prepareRootfs function. Overall I dont see any information generated with my messages.
Please provide any information to understand more of this issue. Please note I am not looking for why this error might have been caused. I am looking for how to get more information from that function of prepareRootfs.

How do I solve the "attempt to call a table value" runtime error on lua?

I'm working on a lua script to convert IO Link data into MQTT. When I debugged the script, I got following runtime error on the function client:register :
Runtime error: attempt to call a table value (global 'string')
I understood that out of the 3 parameters needed, the eventname has to be in string. Coming from Java, I tried converting it directly in the function. It looks like this:
client:register( deviceHandle, string(IOhandleOnDisconnected) , IOhandleOnDisconnected )
It still does not work though.
Does anybody have an idea how to fix this?
Greetings.

string is Lua's standard library for string manipulation. It is a Lua table which cannot be called as you did in string(IOhandleOnDisconnected)

What does this ejabberd / erlang stack trace mean?

could someone help me figure out what to look for in this stacktrace? I've never touched Erlang, so I don't really know where to start.
We're using v19.09 of ejabberd, and getting this error log for many users:
2020-03-14 15:29:31.096 [error] <0.2029.48>#mod_http_api:handle:257 REST API Error: set_presence([{<<"user">>,<<"53265363">>},{<<"host">>,<<"chat.us.com">>},{<<"resource">>,<<"ssid-3465">>},{<<"type">>,<<"available">>},{<<"show">>,<<"chat">>},{<<"status">>,<<"{\"current_lobby_id\":\"none\",\"status\":\"{\\r\
\\t\\\"rich_presence\\\": \\\"{\\\\r\\\
\\\\t\\\\\\\"rich_presence\\\\\\\": \\\\\\\"?s=PlayerStatusInMap?p0=21?p1=2?p2=3\\\\\\\",\\\\r\\\
\\\\t\\\\\\\"session_id\\\\\\\": \\\\\\\"ssid-3465-38a44f60-9df7-4c79-8c8e-1cc99e5039dd\\\\\\\"\\\\r\\\
}\\\",\\r\
\\t\\\"current_lobby_id\\\": \\\"{\\\\r\\\
\\\\t\\\\\\\"lobby_id\\\\\\\": \\\\\\\"c791cfaa-9fd3-4d0d-9d5c-1aeb9efb12e2#hangouts.chat.us.com\\\\\\\",\\\\r\\\
\\\\t\\\\\\\"privacy\\\\\\\": \\\\\\\"friends_only\\\\\\\"\\\\r\\\
}\\\"\\r\
}\",\"region\":\"\"}">>},{<<"priority">>,<<"0">>}]) -> exit:{noproc,{p1_server,call,[none,{set_presence,{presence,<<>>,available,<<>>,{jid,<<"953265363">>,<<"chat.us.com">>,<<"oak/ssid-3465-1cc99e5039dd">>,<<"1953265363">>,<<"chat.us.com">>,<<"4c79-8c8e-1cc99e5039dd">>},{jid,<<"1953265363">>,<<"chat.us.com">>,<<>>,<<"1953265363">>,<<"chat.us.com">>,<<>>},chat,[{text,<<"en">>,<<"{\"current_lobby_id\":\"none\",\"status\":\"{\\r\
\\t\\\"rich_presence\\\": \\\"{\\\\r\\\
\\\\t\\\\\\\"rich_presence\\\\\\\": \\\\\\\"?s=PlayerStatusInMap?p0=21?p1=2?p2=3\\\\\\\",\\\\r\\\
\\\\t\\\\\\\"session_id\\\\\\\": \\\\\\\"ssid-348c8e-1cc99e5039dd\\\\\\\"\\\\r\\\
}\\\",\\r\
\\t\\\"current_lobby_id\\\": \\\"{\\\\r\\\
\\\\t\\\\\\\"lobby_id\\\\\\\": \\\\\\\"c791cfaa-9fd3-4d0d-9d5c-1aeb9efb12e2#hangouts.chat.us.com\\\\\\\",\\\\r\\\
\\\\t\\\\\\\"privacy\\\\\\\": \\\\\\\"friends_only\\\\\\\"\\\\r\\\
}\\\"\\r\
}\",\"region\":\"\"}">>}],0,[],#{}}},1000]}} [{p1_server,call,3,[{file,"src/p1_server.erl"},{line,210}]},{mod_http_api,handle2,4,[{file,"src/mod_http_api.erl"},{line,267}]},{mod_http_api,handle,4,[{file,"src/mod_http_api.erl"},{line,228}]},{mod_http_api,perform_call,4,[{file,"src/mod_http_api.erl"},{line,188}]},{mod_http_api,process,2,[{file,"src/mod_http_api.erl"},{line,141}]},{ejabberd_http,process,2,[{file,"src/ejabberd_http.erl"},{line,366}]},{ejabberd_http,process_request,1,[{file,"src/ejabberd_http.erl"},{line,488}]},{ejabberd_http,process_header,2,[{file,"src/ejabberd_http.erl"},{line,286}]}]

Start with the actual error, which is buried in the middle:
exit:{noproc,{p1_server,call,[none,{set_presence,.....
So there is a noproc error, which occurred during a call to p1_server:call, where the first argument is none. (The call would look like p1_server:call(none, {set_presence,...}).) That is, we're asking the process called none to execute the command set_presence, which fails because there is no process registered with the name none.
Now let's look at the stack trace. I added line breaks:
[{p1_server,call,3,[{file,"src/p1_server.erl"},{line,210}]},
{mod_http_api,handle2,4,[{file,"src/mod_http_api.erl"},{line,267}]},
{mod_http_api,handle,4,[{file,"src/mod_http_api.erl"},{line,228}]},
{mod_http_api,perform_call,4,[{file,"src/mod_http_api.erl"},{line,188}]},
{mod_http_api,process,2,[{file,"src/mod_http_api.erl"},{line,141}]},
{ejabberd_http,process,2,[{file,"src/ejabberd_http.erl"},{line,366}]},
{ejabberd_http,process_request,1,[{file,"src/ejabberd_http.erl"},{line,488}]},
{ejabberd_http,process_header,2,[{file,"src/ejabberd_http.erl"},{line,286}]}]
The first line is where it discovers that there is no such process, on line 210 in p1_server.erl. But we're more interested in why we're passing none as the argument in the first place. The stack trace suggests that's happening somewhere in mod_http_api.erl, but at that point I'm getting lost - it seems like it's extracting the arguments from the command, but I don't understand where the none is coming from...

Lua: How to call error without stack trace

I'm using Lua to parse scripts written in some language (let's call it L) and create Lua-code that can be run by e.g. LuaJIT. But to simplify debugging for the users, I want to map the run time errors given by Lua/LuaJIT to the correct line in the L-files. I do this by xpcalling the created Lua-code, translating the error message and stacktrace and then calling error with this message. Unfortunately this gives me two stack traces, one created by me and one tracing back to the function that called error. Is it possible to get rid of this stack trace, or is there some better way of doing this?
local status, err = xpcall(loadedCode, debug.traceback)
if not status then
error(createANewErrorMessageWithPrettyTraceback(err),0)
end
Output:
luajit: ./my/file.name:5: Some error message
stack traceback:
my pretty traceback
stack traceback:
[C]: in function 'error'
./my/file/calling/error.lua:44: in function <./my/file/calling/error.lua:26>
./my-main:16: in main chunk
[C]: at 0x00404180
I know that e.g. Moonscript does something similar to this, but as far as I can see they just write the new error message to stderr and then continues as normal, instead of stopping the program which is what I want to do.
There is a possibility of doing this and then calling error with no arguments, which will make the program fail (actually I think it's error that fails), but this feels like quite an ugly solution, so I'll rather keep the stupid second trace than doing that.
PS: I assume what the title asks actually doesn't work (as error only takes two arguments), so what I'm actually asking is more how something like this can be achieved. (Are there other functions that do similar things perhaps, or where I should look to figure out how to write that function myself.)
Edit: Is it perhaps possible to edit the function that error's using to get its traceback, as it is with debug.traceback?

I wanted to do something similar (only from Lua directly) and I ended up overwriting debug.traceback function itself to change the stack trace to suit my needs. My code is below; see if this method works for you as well:
local dtraceback = debug.traceback
debug.traceback = function (...)
if select('#', ...) >= 1 then
local err, lvl = ...
if err and type(err) ~= 'thread' then
local trace = dtraceback(err, (lvl or 2)+1)
if genv.print == iobase.print then -- no remote redirect
return trace
else
genv.print(trace) -- report the error remotely
return -- don't report locally to avoid double reporting
end
end
end
-- direct call to debug.traceback: return the original.
-- debug.traceback(nil, level) doesn't work in Lua 5.1
-- (http://lua-users.org/lists/lua-l/2011-06/msg00574.html), so
-- simply remove first frame from the stack trace
return (dtraceback(...):gsub("(stack traceback:\n)[^\n]*\n", "%1"))
end

You could simply display the modified traceback that you want and exit.
local function errh(err)
print(createANewErrorMessageWithPrettyTraceback(debug.traceback(err, 2)))
os.exit(-1) -- error code
end
local status, result = xpcall(loadedCode, errh)
-- The script will never reach this point if there is an error.
print(result)

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