Cannot access symbols in treesit.c when building and running feature/tree-sitter

Question

I'm trying out the feature branch feature/tree-sitter available on remote https://github.com/emacs-mirror/emacs.git.

Build and startup all works fine. However, the functions defined in the Emacs source module treesit.c are not available. For instance the function treesit-language-available-p described in the documentation is not available.

Currently

(require 'treesit nil t)

evaluates to t but

(when (require 'treesit nil t)
  (fboundp 'treesit-language-available-p))

to nil.

Answer 1

I solved it. I had forgotten to pass --with-tree-sitter to ./configure.

On Ubuntu 22.04 this has the prerequisite

apt install libtree-sitter-dev

.