pub fn ambient_kpsewhich_version() -> Option<&'static str>Expand description
The ambient kpsewhich --version banner (full stdout), memoized for the
process. It is a global property of the host TeX install, and several
consumers read it — kpathsea backend selection (select_kpaths) and
ambient-year detection (in latexml_engine; the year-based latex-dump
staleness check in turn consumes that detected year) — so kpsewhich is
spawned at most once. Returns None if kpsewhich is absent or the call
fails.
NOT gated on the kpathsea feature: it is a plain subprocess probe (no C
library), so the year/stamp logic can share it even in the host-side codegen
build. Lives here — the lowest crate that constructs Kpaths — so both the
backend choice and latexml_engine resolve the same single spawn.