glib/gdate.c: In function ‘g_date_add_months’:
glib/gdate.c:1732:27: error: comparison of integer expressions of different signedness: ‘guint’ {aka ‘unsigned int’} and ‘int’ [-Werror=sign-compare]
   g_return_if_fail (years <= G_MAXUINT16 - d->year);
                           ^~
glib/gmacros.h:455:25: note: in definition of macro ‘G_LIKELY’
 #define G_LIKELY(expr) (expr)
                         ^~~~
glib/gdate.c:1732:3: note: in expansion of macro ‘g_return_if_fail’
   g_return_if_fail (years <= G_MAXUINT16 - d->year);
   ^~~~~~~~~~~~~~~~
glib/gdate.c: In function ‘g_date_add_years’:
glib/gdate.c:1816:28: error: comparison of integer expressions of different signedness: ‘guint’ {aka ‘unsigned int’} and ‘int’ [-Werror=sign-compare]
   g_return_if_fail (nyears <= G_MAXUINT16 - d->year);
                            ^~
glib/gmacros.h:455:25: note: in definition of macro ‘G_LIKELY’
 #define G_LIKELY(expr) (expr)
                         ^~~~
glib/gdate.c:1816:3: note: in expansion of macro ‘g_return_if_fail’
   g_return_if_fail (nyears <= G_MAXUINT16 - d->year);
   ^~~~~~~~~~~~~~~~