Comment 24 for bug 1396758

I can confirm that this bug seems to have re-emerged. On a fully updated system:

mlcurry@ubuntu:~/tmp$ sudo apt-get -qq update
mlcurry@ubuntu:~/tmp$ sudo apt-get -qq dist-upgrade
mlcurry@ubuntu:~/tmp$ apt-get -qq source lttng-modules
gpgv: Signature made Wed 26 Nov 2014 01:19:42 PM MST using RSA key ID 64792D67
gpgv: Can't check signature: public key not found
dpkg-source: warning: failed to verify signature on ./lttng-modules_2.4.0-1ubuntu1.1.dsc
dpkg-source: info: extracting lttng-modules in lttng-modules-2.4.0
dpkg-source: info: unpacking lttng-modules_2.4.0.orig.tar.gz
dpkg-source: info: unpacking lttng-modules_2.4.0-1ubuntu1.1.debian.tar.gz
dpkg-source: info: applying fix-build-on-ubuntu-kernels.patch
mlcurry@ubuntu:~/tmp$ cd lttng-modules-2.4.0/
mlcurry@ubuntu:~/tmp/lttng-modules-2.4.0$ make
make -C /lib/modules/3.16.0-46-generic/build M=/home/mlcurry/tmp/lttng-modules-2.4.0 modules
make[1]: Entering directory `/usr/src/linux-headers-3.16.0-46-generic'
  CC [M] /home/mlcurry/tmp/lttng-modules-2.4.0/lttng-ring-buffer-client-discard.o
  CC [M] /home/mlcurry/tmp/lttng-modules-2.4.0/lttng-ring-buffer-client-overwrite.o
  CC [M] /home/mlcurry/tmp/lttng-modules-2.4.0/lttng-ring-buffer-metadata-client.o
  CC [M] /home/mlcurry/tmp/lttng-modules-2.4.0/lttng-ring-buffer-client-mmap-discard.o
  CC [M] /home/mlcurry/tmp/lttng-modules-2.4.0/lttng-ring-buffer-client-mmap-overwrite.o
  CC [M] /home/mlcurry/tmp/lttng-modules-2.4.0/lttng-ring-buffer-metadata-mmap-client.o
  CC [M] /home/mlcurry/tmp/lttng-modules-2.4.0/lttng-statedump-impl.o
/home/mlcurry/tmp/lttng-modules-2.4.0/lttng-statedump-impl.c: In function ‘lttng_statedump_process_ns’:
/home/mlcurry/tmp/lttng-modules-2.4.0/lttng-statedump-impl.c:310:2: error: implicit declaration of function ‘task_nsproxy’ [-Werror=implicit-function-declaration]
  proxy = task_nsproxy(p);
  ^
/home/mlcurry/tmp/lttng-modules-2.4.0/lttng-statedump-impl.c:310:8: warning: assignment makes pointer from integer without a cast [enabled by default]
  proxy = task_nsproxy(p);
        ^
cc1: some warnings being treated as errors
make[2]: *** [/home/mlcurry/tmp/lttng-modules-2.4.0/lttng-statedump-impl.o] Error 1
make[1]: *** [_module_/home/mlcurry/tmp/lttng-modules-2.4.0] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-3.16.0-46-generic'
make: *** [default] Error 2