bass VS BuildXL

We spent some time evaluating this on my team, and we're still experimenting with it.

I like it a lot, but the project appears to be mostly unmaintained since mid-2021, when the creator left it to work on a lispy CI/CD tool [0] that feels very complicated... not sure what's going on there.

[0]: https://github.com/vito/bass

vito/bass is a cool, well done scripting language implemented in Go with an LSP, I think. Here's the entrypoint: https://github.com/vito/bass/blob/main/cmd/bass/lsp.go

I've been following https://github.com/vito/bass which is a LISP implemented in Go

Looks like it takes some inspiration from Clojure but isn't based on it: https://github.com/vito/bass#kernels-influence

Seems they came up with a way to scale up build toolchains with BuildXL[0]

Doesn't seem fully baked yet though

[0]: https://github.com/microsoft/BuildXL

> With regards to chroot, I stand corrected. I knew it was a tree of symlinks, but I thought it was also more than that because symlinks alone don't seem like a sandbox. Honestly, Cosmopolitan's system appears to be more of a sandbox than that.

To be totally clear: the tree of symlinks thing is a fallback, used only when lacking platform support or when sandboxing is explicitly turned off [0]. On Linux, the normal sandboxing strategy is to use namespaces, like most container runtimes. On Mac it apparently uses sandbox-exec (some opaque Apple tool), as was mentioned above. Chroot, being both non-POSIX, requiring root access on many systems, and not providing the necessary facilities is not really a great fit -- which I assume is why it's not used.

There was experimental Windows sandbox support at one point [1] based on how MS does it for BuildXL (their own build tool for giant monorepos) [2]. Unfortunately it doesn't seem to be maintained, and under the hood it's kinda ugly -- it actively rewrites code in-memory to intercept calls to the Win32 APIs [3], which was apparently the cleanest/best way MS could come up with. However, from Bazel's POV it works in a roughly similar way -- you spawn subprocesses under a supervisor, which is in charge of spinning up whatever the target process is with restrictions on time/memory usage/file access.

On the "sandbox in the interpreter" thing: what kind of checks are you envisioning? It seems like putting checks at that level would end up leaving a lot out -- the goal of any build system is to eventually spawn an arbitrary process (Python, gcc, javac, some shell script, etc.) and so even with extensive checks in starlark you'd end up with accidental sandbox breaks all over the place. For pure starlark rules you could e.g. check that there are no inputs from /usr, but even then if gcc does it implicitly, you're SOL. Or am I thinking of the wrong kind of checks?

[0] https://bazel.build/docs/sandboxing#sandboxing-strategies

[1] https://github.com/bazelbuild/bazel/issues/5136#issuecomment...

[2] https://github.com/microsoft/BuildXL/blob/master/Documentati...

[3] https://github.com/microsoft/Detours/wiki