cc -O2 -pipe  -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations signal/ucontext_t-uc_mcontext.c -o signal/ucontext_t-uc_mcontext -D_POSIX_C_SOURCE=202405L  -lm -lpthread 
signal/ucontext_t-uc_mcontext.c:4:2: error: unknown type name 'mcontext_t'; did you mean 'ucontext_t'?
        mcontext_t *qux = &bar->uc_mcontext;
        ^~~~~~~~~~
        ucontext_t
/usr/include/sys/signal.h:190:27: note: 'ucontext_t' declared here
typedef struct sigcontext ucontext_t;
                          ^
signal/ucontext_t-uc_mcontext.c:4:26: error: no member named 'uc_mcontext' in 'struct sigcontext'
        mcontext_t *qux = &bar->uc_mcontext;
                           ~~~  ^
2 errors generated.