Standard library is another factor. Lua does not come with any batteries. Even sockets are an external dependencies. So you would need to ship (and maintain) a lot of libs.

I suspect they would need the lua-posix extension, which appears to be maintained by a fairly small number of people. Lua doesn't have some basic stuff they would want, like stat(), chmod(), sleep().

Edit: Sort of makes me wonder why a VERY C-like, small, dynamically typed, scripting language never emerged. Squirrel is kind of close, but not quite what I mean.

>> Sort of makes me wonder why a VERY C-like, small, dynamically typed, scripting language never emerged.

Csh (https://en.wikipedia.org/wiki/C_shell) was the de facto standard shell on many Unix systems and still is widely used.

However, it has some issues:

http://www.faqs.org/faqs/unix-faq/shell/csh-whynot/

https://www.grymoire.com/Unix/CshTop10.txt

That might me the direction FreeBSD follows. It started with integrating Lua into the bootloader, replacing Forth. There’s now also the userspace flua(1) interpreter, used in a few places in the build system, IIRC.

Generally- so far, flua only drives the generation of the various files we derive from syscalls.master.

There's been some WIP to also use it for some pkgbase stuff, as well as an ldconfig lua script for use in post-install scripts now that pkg supports post-install.lua.

I've had my eye on a couple of other components that could use a rewrite with flua. A new flua-based replacement for kernel config(8) could be quite excellent, for instance.