[1vuio0pswjnm7]

"Because Pnut can be distributed as a human-readable shell script (`pnut.sh`), it can serve as the basis for a reproducible build system. With a POSIX compliant shell, `pnut.sh` is sufficiently powerful to compile itself and, with some effort, [TCC](https://bellard.org/tcc/). Because TCC can be used to bootstrap GCC, this makes it possible to bootstrap a fully featured build toolchain from only human-readable source files and a POSIX shell.

Because Pnut doesn't support certain C features used in TCC, Pnut features a native code backend that supports a larger subset of C99. We call this compiler `pnut-exe`, and it can be compiled using `pnut.sh`. This makes it possible to compile `pnut-exe.c` using `pnut.sh`, and then compile TCC, all from a POSIX shell."

Anywhere we can see a step-by-step demo of this process.

Curious if the authors tried NetBSD or OpenBSD, or using another small C compiler, e.g., pcc.

Historically, tcc was problematic for NetBSD and its forks. Not sure about today, but tcc is still in NetBSD pkgsrc WIP which suggests problems remain.

[kazinator]

Problem is:

- a shell is required, which has to be built from sources, using a compiler which was also built from sources using a compile binary. That's the real boostrap.

- even if you could pick some shell, and compiled it with pnut.exe, the compiled code requires interpretation by an executable shell.

- there is no such thing as a "POSIX compliant shell"; that's an abstract category. All this amounts to is a promise that pnut.sh will not generate code that uses non-POSIX features.