guest cc: cc 8.3 [DragonFly] Release/2019-02-22
$ cd /tmp/df4852 && cc -O -Wall -o dm_chunk dm_chunk.c -lprop
(no diagnostics; exit 0)
$ ls -la dm_chunk
-rwxr-xr-x  1 root  wheel  14408 Sep 24 14:16 dm_chunk
BUILD OK: exit 0
NOTE: full run outputs: run.log (baseline, UNPATCHED module: cases A/C accepted), fix_run.log (PATCHED module: cases A/C -> EINVAL)