I had issues updating libtorrent to new version (0.13.4 -> 0.13.6)
Code:
# sboupgrade libtorrent
[...]
/usr/lib64/gcc/x86_64-slackware-linux/4.8.2/../../../../x86_64-slackware-linux/bin/ld: skipping incompatible /usr/lib/libz.so when searching for -lz
/usr/lib64/gcc/x86_64-slackware-linux/4.8.2/../../../../x86_64-slackware-linux/bin/ld: skipping incompatible /usr/lib/libz.a when searching for -lz
/usr/lib64/gcc/x86_64-slackware-linux/4.8.2/../../../../x86_64-slackware-linux/bin/ld: skipping incompatible /usr/lib/libcrypto.so when searching for -lcrypto
/usr/lib64/gcc/x86_64-slackware-linux/4.8.2/../../../../x86_64-slackware-linux/bin/ld: skipping incompatible /usr/lib/libcrypto.a when searching for -lcrypto
/usr/lib64/../lib/libstdc++.so: could not read symbols: File in wrong format
collect2: error: ld returned 1 exit status
make[3]: *** [libtorrent.la] Error 1
make[3]: Leaving directory `/tmp/SBo/libtorrent-0.13.6/src'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/tmp/SBo/libtorrent-0.13.6/src'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/tmp/SBo/libtorrent-0.13.6'
make: *** [all] Error 2
Failures:
libtorrent: libtorrent.SlackBuild return non-zero
The system is a Slackware 14.1, 64 bit, with Alien multilib packages (updated).