broadcom-sta-dkms (6.30.223.271-7) の compile に以下の通り fail する．
[/var/lib/dkms/broadcom-sta/6.30.223.271/build/make.log] 抜粋
Kernel architecture is X86_64
AR /var/lib/dkms/broadcom-sta/6.30.223.271/build/built-in.o
CC [M] /var/lib/dkms/broadcom-sta/6.30.223.271/build/src/shared/linux_osl.o
In file included from ./include/linux/compat.h:17:0,
from ./include/linux/ethtool.h:17,
from ./include/linux/netdevice.h:41,
from /var/lib/dkms/broadcom-sta/6.30.223.271/build/src/include/linuxver.h:69,
from /var/lib/dkms/broadcom-sta/6.30.223.271/build/src/shared/linux_osl.c:25:
./include/linux/if.h:28:10: fatal error: sys/socket.h: No such file or directory
#include <sys/socket.h> /* for struct sockaddr. */
^~~~~~~~~~~~~~
compilation terminated.https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=862175 にあるとおりinclude/uapi/linux/if.hが使われるべきで，include/linux/if.hは存在しないべき(？)だそう．include/uapi/linux/if.hが存在すれば /usr/src/linux-headers-<version>/include/linux/if.h を削除してしまえば解決する．