mkc_check_prog(1) on Linux
The text 85368624d3c1, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
detects presense of header file.
Flags it lists
-
-h