None of these flags cause warnings anymore, so no fixes necessary.
The flags are:
-Wformat-nonliteral
-Wformat-security
-Wold-style-definition
-Wcast-align
-Winline
-Winit-self
-Wmissing-include-dirs
-Waddress
-Waggregate-return
-Wno-multichar
-Wnested-externs
AC_SUBST(GST_PKG_DEPS)
dnl define an ERROR_CFLAGS Makefile variable
-AG_GST_SET_ERROR_CFLAGS($GST_GIT, [-Wmissing-declarations -Wmissing-prototypes -Wredundant-decls -Wundef -Wwrite-strings])
+AG_GST_SET_ERROR_CFLAGS($GST_GIT, [-Wmissing-declarations -Wmissing-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wformat-nonliteral -Wformat-security -Wold-style-definition -Wcast-align -Winline -Winit-self -Wmissing-include-dirs -Waddress -Waggregate-return -Wno-multichar -Wnested-externs])
dnl define correct level for debugging messages
AG_GST_SET_LEVEL_DEFAULT($GST_GIT)