In fact, it's due to a new-ish change in GCC-land; on some versions, tgmath (type-generic maths) works fine for log10, but it seems they've changed that. Furthermore, clog10 (the complex version) is actually a GNU extension rather than part of C99, so I've adjusted ops.pd accordingly (and if there's no clog10 available, you can't do log10 on complex numbers, sorry - but it was ever thus).

I've just released PDL 2.060 which I believe fixes this, so please give it a try.