nx_probe_linemap_live.nx

nx_probe_linemap_live.nx -- WITNESS for the per-file line map (nx_linemap.nx). The witness works by making the two answers impossible to confuse. This file imports nx_syscalls.nx (~46 KB, ~1200 lines), so the undefined call below sits at a SMALL line in THIS file and a LARGE line in the flattened expanded buffer: BEFORE (no map): error at line ~1200: I do not know the name ... AFTER (map on): error at nx_probe_linemap_live.nx:<small>: I do not know the name ... Three orders of magnitude apart, and the AFTER names the file. No judgement call. expect_exit: nonzero -- this file is SUPPOSED to fail to compile.