~$ auto-apt search libdl.so.2
lib/libdl.so.2  libs/libc6
usr/lib/debug/libdl.so.2        libdevel/libc6-dbg

$ apt-file search libdl.so.2
libc6: lib/libdl.so.2
libc6-amd64: lib64/libdl.so.2
libc6-dbg: usr/lib/debug/libdl.so.2
libc6-i686: lib/i686/cmov/libdl.so.2
libc6-xen: lib/i686/nosegneg/libdl.so.2
systemimager-boot-i386-standard: usr/share/systemimager/boot/i386/standard/initrd_template/lib/libdl.so.2
systemimager-boot-ia64-standard: usr/share/systemimager/boot/ia64/standard/initrd_template/lib/libdl.so.2