ZeroBrane Studio supports remote debugging that allows to debug arbitrary Lua applications. The application may be running on the same or a different computer from the one running the IDE instance (the debugger is using a socket interface to interact with the application).

Remote debugging

  • Launch the IDE. Go to Project | Start Debugger Server and start the debugger server (if this menu item is checked, the server is already started).
  • Open the Lua file you want to debug.
  • Select the project directory by going to Project | Project Directory | Choose... or using Project | Project Directory | Set From Current File.
  • Add require('mobdebug').start() call to your file. If the application is running on a different computer, you need to specify an address of the computer running the IDE as the first parameter to the start() call: require('mobdebug').start("12.345.67.89") or require('mobdebug').start(""). You can see the domain name to connect to in the Output window when you start debugger server: Debugger server started at <domain>:8172.
  • Make mobdebug.lua and luasocket available to your application. This can be done in one of three ways:
    1. Set LUA_PATH and LUA_CPATH before starting your application (see Setup environment for debugging);
    2. Reference path to mobdebug.lua and luasocket using package.path and package.cpath (see Configure path for debugging); or
    3. Include mobdebug.lua with your application by copying it from lualibs/mobdebug/mobdebug.lua (this assumes your application already provides luasocket support).
  • Run your application. You should see a green arrow pointing to the next statement after the start() call in the IDE and should be able to step through the code.

Setup environment for debugging

Running debugging with your application requries loading of mobdebug and luasocket modules. These libraries are packaged with the IDE for all supported platforms (Windows/macOS/Linux) and Lua versions (5.1, 5.2, and 5.3).

You can use a simple script to set LUA_PATH and LUA_CPATH environmental variables to reference mobdebug and luasocket files that come with the IDE:

set ZBS=D:\path\to\ZeroBraneStudio
set LUA_PATH=./?.lua;%ZBS%/lualibs/?/?.lua;%ZBS%/lualibs/?.lua
set LUA_CPATH=%ZBS%/bin/?.dll;%ZBS%/bin/clibs/?.dll

If you are running this on Linux, make sure you use the same path separator (;) and reference proper location depending on your Linux architecture (replace x86 with x64 if you are running this on a 64bit system):

export ZBS=/opt/zbstudio
export LUA_PATH="./?.lua;$ZBS/lualibs/?/?.lua;$ZBS/lualibs/?.lua"
export LUA_CPATH="$ZBS/bin/linux/x86/?.so;$ZBS/bin/linux/x86/clibs/?.so"

Note that these instructions are for Lua 5.1- and LuaJIT-based systems. If your application is using Lua 5.2 or Lua 5.3 interpreters, then replace clibs in LUA_CPATH values with clibs52 or clibs53, respectively, to load proper versions of the required modules.

Debugging of 64bit applications

If you are debugging a 64bit application on Windows, you need to make the 64bit luasocket library available to your application and set package.cpath appropriately (to make sure it references 64bit libraries before any other library that may be referenced there) as the libraries included with the IDE are compiled for 32bit architecture and will not work with 64bit applications.

macOS and Linux don’t require any special handling for 64bit applications as Linux version are available for both 32bit and 64bit architectures and macOS libraries are compiled as universal libraries (and can be loaded from 32bit and 64bit applications).

If you also plan to launch the 64bit application from the IDE (instead of or in addition to launching it outside of the IDE), you need to configure path.lua to point to the location of your Lua executable (as described in the general preferences section).

Configure path for debugging

In a similar way, instead of specifying LUA_PATH and LUA_CPATH, you can set package.path and package.cpath (if needed) directly from your script:

package.path = package.path .. ";/opt/zbstudio/lualibs/mobdebug/?.lua"


See Debugging Wireshark lua scripts for detailed description on how this remote debugging works with Wireshark scripts.


  • How do I find a path to mobdebug.lua? mobdebug.lua is located in lualibs/mobdebug directory under your ZeroBrane Studio installation directory. The location of ZeroBrane Studio is system dependent; on Windows it is the location of the directory you installed ZeroBrane Studio to; on Linux it is /opt/zbstudio; and on macOS it is /Applications/ (You may need to right click on the application and select Show Package Contents to navigate to that location on macOS).

  • I can’t step into functions defined in other files in my project. You either need to open them in the IDE before you want to step through them, or to configure the IDE to auto-open files requested during debugging using editor.autoactivate = true.

  • Breakpoints are not triggered. You may want to check this FAQ answer for possible reasons and suggestions on how to fix this.

  • The host name is detected incorrectly. In some rare cases the domain name detected by ZeroBrane Studio cannot be resolved, which prevents the debugger from working. You can specify the domain name or address you want to use by configuring the IDE with debugger.hostname="domain".

  • I get dynamic libraries not enabled error. You may get the following error when loading socket.core on Linux: error loading module ‘socket.core’ from file ‘/opt/zstudio/bin/linux/x86/clibs/socket/’: dynamic libraries not enabled; check your Lua installation. This most likely means that the Lua interpreter you are using was built without LUA_USE_DLOPEN option enabled. You can either enable it or statically link your application with luasocket.

  • (Note: you should not see this error if you are using v0.38 or later) I get “Debugger error: unexpected response after EXEC/LOAD ‘201 Started …’”. This is caused by not having a filename associated with a dynamic chunk loaded by your application. If you are using loadstring(), you should pass a second parameter that is a filename for the fragment (and that file can then be debugged in ZeroBrane Studio if it’s placed in the project directory). If you are using luaL_loadstring (which has no option to label the chunk with its file path), you can switch to using luaL_loadbuffer to pass that information.

what a breath of fresh air. (doctorbling)

IMHO, ZBS is the fastest, most-flexible, best-thought-out IDE AND Debugger I've used since I began coding professionally in 1980. (Michael Berlyn)

Love ZeroBrane Studio. Lightweight. Works. Powerful. (Ross Berteig)

Love the debugger, saving my life. (Troy Sandal)

Thanks again for your awesome IDE. I've moved over to it, forsaking my previous investment in Decoda! (Stephen Nichols)

my kids love ZeroBrane. (Phil Hagelberg)

ZBS is beautiful experience. I am using it usually 10 hrs every day w/o problems. (Srdjan Markovic)

...heartily recommend it. (stun)

I love ZBS. I use it for all of the work I’ve started doing in Lua...! This IDE is fantastic! (Eddie Dover)

ZeroBrane Studio has got a working debugger, full IDE feature set, small footprint, and is completely customizable in lua. You have no idea how excited I was to find this little gem! (Jonathan Shieh)

It's a joy to use;... totally rock solid. (Jeff Smith)

Complaining about Zerobrane is like complaining that a beautiful spring day is a couple degrees too warm. (Jim Burnes)