Root cause: sx_browser.ml registered all HTML tags (a, b, i, p, s, u, g, etc.)
as custom special forms. The evaluator's step_eval_list checked custom special
forms BEFORE checking local env bindings. So (let ((a (fn () 42))) (a))
matched the HTML tag <a> instead of calling the local function a.
Fix: skip custom special forms AND render-check when the symbol is bound in
the local env. Added (not (env-has? env name)) guard to both checks in
step-eval-list (spec/evaluator.sx and transpiled sx_ref.ml).
This was the root cause of "[sx] resume: Not callable: nil" — after hs-wait
resumed, calling letrec-bound functions like wait-boot (which is not an HTML
tag) worked, but any function whose name collided with an HTML tag failed.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
giles
c641b445f8