As reported in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=782820
iksemel FTBFS against the recently released GnuTLS 3.4.0:
--------------------------
/bin/bash ../libtool  --tag=CC   --mode=link gcc  -g -O2 -fPIE 
-fstack-protector-strong -Wformat -Werror=format-security -Wall  -fPIE -pie 
-Wl,-z,relro -Wl,-z,now -o ikslint ikslint.o hash.o ../src/libiksemel.la
libtool: link: gcc -g -O2 -fPIE -fstack-protector-strong -Wformat 
-Werror=format-security -Wall -fPIE -pie -Wl,-z -Wl,relro -Wl,-z -Wl,now -o 
.libs/ikslint ikslint.o hash.o  ../src/.libs/libiksemel.so
../src/.libs/libiksemel.so: undefined reference to `gnutls_mac_set_priority'
../src/.libs/libiksemel.so: undefined reference to 
`gnutls_protocol_set_priority'
../src/.libs/libiksemel.so: undefined reference to `gnutls_kx_set_priority'
../src/.libs/libiksemel.so: undefined reference to `gnutls_cipher_set_priority'
../src/.libs/libiksemel.so: undefined reference to 
`gnutls_compression_set_priority'
collect2: error: ld returned 1 exit status
Makefile:386: recipe for target 'ikslint' failed
make[2]: *** [ikslint] Error 1
make[2]: Leaving directory '/tmp/buildd/libiksemel-1.4/tools'
--------------------------
These functions were dropped in 3.4.0, see
http://www.gnutls.org/manual/html_node/Upgrading-from-previous-versions.html#Upg
rading-from-previous-versions
for information on upgrading.