I inspected slim-1.4.0/app.h and found that -1.4.1/app.h was missing (purposefully?) these lines: #include <X11/Xlib.h> #include <signal.h> #include <unistd.h> #include <sys/wait.h> #include <errno.h> #include <setjmp.h> #include <stdlib.h> #include <iostream> #include "panel.h" #include "cfg.h" #include "image.h" I added them to -1.4.1/app.h and it compiled without error.
Error 2 Compiling v1.4.1