Permission Denied When Building in Sublime Text 3 - windows

Question

I am attempting to utilize Lua on Windows 10 with Sublime Text 3. When I attempt to build and run a script I receive the following error:
lua: cannot open C:\Program Files (x86)\Lua\5.1: Permission denied
I have added full permissions to the folder.
I am only attempting to run a simple print statement:
print("hello")
The expected result is hello output in the results window.

Answer 1

The build system that ships with Sublime for executing Lua programs looks like this:
{
"cmd": ["lua", "$file"],
"file_regex": "^(?:lua:)?[\t ](...*?):([0-9]*):?([0-9]*)",
"selector": "source.lua"
}
The important aspect here is that the command to be executed is lua with a first argument that is the name of the current file. From the error message you're seeing, Lua looks like it's trying to execute a directory instead of the name of a program. Or if you will, if this was a directory permission problem I would expect it to tell you the name of the file that it can't access, not the folder than the file is stored in.
It's also suspicious that the name of the folder is the install location for lua itself, and that the error message seems to indicate that it's lua itself generating the error.
Based on all of this, my guess would be that you didn't save your Lua script before you executed the command. That would cause $file to expand out to an empty string, making the first argument empty. Since the build is using cmd, internally windows is being told specifically to run a program named lua with an empty string as it's first argument.
It looks like the interpreter first tries to put the current working directory onto the filename and then execute it, and since the file name is empty, it ends up trying to execute a directory, which is where the permission problem comes from.
Once you save the file the first time and it has a name, Sublime will automatically re-save it every time you run the build as long as Tools > Save all on build is checked; that option won't prompt you to save brand new files that don't have names yet, though.