Why would you want somebody to be able to chdir or otherwise manipulate global state in, say, a dialog script for a game engine, though? You probably don't. You probably don't want them to be able to do lots of things. Hence the standard library lacking most things.
Yes, having a package manager might solve some issues, but not for any of Lua's primary use cases. It's not supposed to be the language you write your web app in, or a shell script replacement, or whatever else, and the language developers really don't care about those use cases. It's not supposed to be anything out of the box aside from some syntax and semantics that are Turing-complete and reasonably usable.
Where I've seen Lua used, often even the existing standard library is modified or not used at all due to constraints from the embedding program. What point is a package manager if you can't use most of the packages in many environments? This isn't just embedded ones - this is on the desktop as well.
If you're looking for something more capable out-of-the-box, I'd go for embedding Python or Ruby. Lua simply serves a different niche.
Yes, having a package manager might solve some issues, but not for any of Lua's primary use cases. It's not supposed to be the language you write your web app in, or a shell script replacement, or whatever else, and the language developers really don't care about those use cases. It's not supposed to be anything out of the box aside from some syntax and semantics that are Turing-complete and reasonably usable.
Where I've seen Lua used, often even the existing standard library is modified or not used at all due to constraints from the embedding program. What point is a package manager if you can't use most of the packages in many environments? This isn't just embedded ones - this is on the desktop as well.
If you're looking for something more capable out-of-the-box, I'd go for embedding Python or Ruby. Lua simply serves a different niche.