cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations fmtmsg/MM_NULLTXT.c -o fmtmsg/MM_NULLTXT -D_POSIX_C_SOURCE=202405L -lm -lpthread -lnetwork -lbsd -latomic
fmtmsg/MM_NULLTXT.c:7:10: fatal error: fmtmsg.h: No such file or directory
    7 | #include <fmtmsg.h>
      |          ^~~~~~~~~~
compilation terminated.