This bug will be fixed with the introduction of musl_1.0.0-1 upwards. There is now a global link /usr/bin/musl-ldd that can be invoked with musl-ldd <MUSLBINARY>
If you still prefer to access the ldd functionality via the command ldd, then follow the instructions found under: http://wiki.musl-libc.org/wiki/FAQ#Q:_where_is_ldd_.3F