Both libimg.so and libcbf.so use symbols from libm, but don't link with it. It may cause problems with '--as-needed'. Fix is trivial - adding '-lm' at the end of those two lines in the current patch (0.8.1-Makefile.patch).
I don't think that is true, because I am using as-needed by default. But I will look into it.
Well, I'm not 100% sure, it's a problem, but 'ldd -r' will confirm, they are underlinked. Perhaps with recent binutils the effect is not as noticeable, as it was before.
Right that doesn't look good. I will fix that.
Fixed. Thanks for reporting.