I am not sure why he is claiming that it is linked against both of them but:
ldd usr/lib/perl5/auto/DBD/mysql/mysql.so libmysqlclient.so.12 => /usr/lib/libmysqlclient.so.12 (0x40026000) libz.so.1 => /usr/lib/libz.so.1 (0x40066000) libcrypt.so.1 => /lib/tls/i686/cmov/libcrypt.so.1 (0x40077000) libnsl.so.1 => /lib/tls/i686/cmov/libnsl.so.1 (0x400a3000) libm.so.6 => /lib/tls/i686/cmov/libm.so.6 (0x400b7000) libssl.so.0.9.7 => /usr/lib/i686/cmov/libssl.so.0.9.7 (0x400da000) libcrypto.so.0.9.7 => /usr/lib/i686/cmov/libcrypto.so.0.9.7 (0x40109000) libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0x401ff000) /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000) libdl.so.2 => /lib/tls/i686/cmov/libdl.so.2 (0x40332000)
from debian and we have a similar output (only v12 linked).
I am not sure why he is claiming that it is linked against both of them but:
ldd usr/lib/ perl5/auto/ DBD/mysql/ mysql.so
libmysqlclien t.so.12 => /usr/lib/ libmysqlclient. so.12 (0x40026000)
libcrypt. so.1 => /lib/tls/ i686/cmov/ libcrypt. so.1 (0x40077000) i686/cmov/ libnsl. so.1 (0x400a3000) i686/cmov/ libm.so. 6 (0x400b7000)
libssl. so.0.9. 7 => /usr/lib/ i686/cmov/ libssl. so.0.9. 7 (0x400da000)
libcrypto. so.0.9. 7 => /usr/lib/ i686/cmov/ libcrypto. so.0.9. 7 (0x40109000) i686/cmov/ libc.so. 6 (0x401ff000)
/lib/ld- linux.so. 2 => /lib/ld-linux.so.2 (0x80000000) i686/cmov/ libdl.so. 2 (0x40332000)
libz.so.1 => /usr/lib/libz.so.1 (0x40066000)
libnsl.so.1 => /lib/tls/
libm.so.6 => /lib/tls/
libc.so.6 => /lib/tls/
libdl.so.2 => /lib/tls/
from debian and we have a similar output (only v12 linked).