src/receiver1 | 2 1 + 1 - 0 !
src/receiver2 | 2 1 + 1 - 0 !
2 files changed, 2 insertions(+), 2 deletions(-)

 this script is marked as running under /bin/sh, but it seems to use a
feature found in bash but not in the SUSv3 or POSIX shell specification.

src/Makefile | 1 1 + 0 - 0 !
1 file changed, 1 insertion(+)

 in accordance with debian's hardening rules [1], cppflags is required.
[1] https://wiki.debian.org/HardeningWalkthrough#Enabling_dpkg-buildflags_in_your_debian.2Frules_files