Something

make[4]: Entering directory `/home/andreas/openwrt/trunk/build_mipsel/nsca-2.6'
cd ./src/; make send_nsca ; cd ..
make[5]: Entering directory `/home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/src'
mipsel-linux-uclibc-gcc -Os -pipe -mips32 -mtune=mips32 -funit-at-a-time -I/home/andreas/openwrt/trunk/staging_dir_mipsel/usr/include -I/home/andreas/openwrt/trunk/staging_dir_mipsel/include -I/home/andreas/openwrt/trunk/staging_dir_mipsel/usr/include -I/home/andreas/openwrt/trunk/staging_dir_mipsel/include -I/home/andreas/openwrt/trunk/staging_dir_mipsel/usr/include -I/home/andreas/openwrt/trunk/staging_dir_mipsel/include -DHAVE_LIBMCRYPT  -DHAVE_CONFIG_H -o send_nsca send_nsca.c netutils.c utils.c -L/home/andreas/openwrt/trunk/staging_dir_mipsel/usr/lib -L/home/andreas/openwrt/trunk/staging_dir_mipsel/lib   -lnsl
/tmp/ccmZJcC4.o: In function `encrypt_cleanup':
utils.c:(.text+0xf4): undefined reference to `mcrypt_generic_end'
/tmp/ccmZJcC4.o: In function `encrypt_init':
utils.c:(.text+0x468): undefined reference to `mcrypt_module_open'
utils.c:(.text+0x4b0): undefined reference to `mcrypt_enc_get_iv_size'
utils.c:(.text+0x534): undefined reference to `mcrypt_enc_get_key_size'
utils.c:(.text+0x5ec): undefined reference to `mcrypt_generic_init'
/tmp/ccmZJcC4.o: In function `encrypt_buffer':
utils.c:(.text+0x714): undefined reference to `mcrypt_generic'
/tmp/ccmZJcC4.o: In function `decrypt_buffer':
utils.c:(.text+0x7d0): undefined reference to `mdecrypt_generic'
collect2: ld returned 1 exit status
make[5]: *** [send_nsca] Error 1
make[5]: Leaving directory `/home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/src'
make[4]: Leaving directory `/home/andreas/openwrt/trunk/build_mipsel/nsca-2.6'
touch /home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/.built
install -d -m0755 /home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/ipkg/send-nsca/etc
install -m0600 /home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/sample-config/send_nsca.cfg /home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/ipkg/send-nsca/etc/
install -d -m0755 /home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/ipkg/send-nsca/usr/sbin
install -m0755 /home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/src/send_nsca /home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/ipkg/send-nsca/usr/sbin/
install: cannot stat `/home/andreas/openwrt/trunk/build_mipsel/nsca-2.6/src/send_nsca': No such file or directory
make[3]: *** [/home/andreas/openwrt/trunk/bin/packages/send-nsca_2.6-1_mipsel.ipk] Error 1
make[3]: Leaving directory `/home/andreas/openwrt/packages/net/nsca'
make[2]: *** [nsca-compile] Error 2
make[2]: Leaving directory `/home/andreas/openwrt/trunk/package'
make[1]: *** [package/compile] Error 2
make[1]: Leaving directory `/home/andreas/openwrt/trunk'
make: *** [world] Error 2