cc -O2 -pipe  -pthread  -Wall -Wextra -Werror=implicit-function-declaration time/getdate.c -o time/getdate -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm -lpthread 
time/getdate.c:44:18: error: call to undeclared function 'getdate'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
        struct tm* tm = getdate("2000-01-01 02:03:04");
                        ^
time/getdate.c:44:13: warning: incompatible integer to pointer conversion initializing 'struct tm *' with an expression of type 'int' [-Wint-conversion]
        struct tm* tm = getdate("2000-01-01 02:03:04");
                   ^    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
time/getdate.c:46:33: error: use of undeclared identifier 'getdate_err'
                errx(1, "getdate failed: %i", getdate_err);
                                              ^
1 warning and 2 errors generated.