libgoogle-perftools-dev: missing dependency on libunwind8-dev ?

Hi there

I'm not sure if this is a bug, so I've decided to figure it out first before posting a ticket to the bugtracker.

I'm using static version of libprofiler (provided by libgoogle-perftools-dev package) on amd64 platform on one of my projects and as far as I understand, libprofiler.a depends on some symbols that should be provided by libunwind:

# distinct undefined symbols in libprofiler
$ nm -C /usr/lib/libprofiler.a | grep ' U ' | awk '{print $2}' | sort -u > libprofiler_undefined_syms.txt

# distinct defined symbols in libunwind
$ nm -C /usr/lib/libunwind.a | grep '^0' | awk '{print $3}' | sort -u > libunwind_defined_syms.txt

# intersect those lists:
$ comm -12 libprofiler_undefined_syms.txt libunwind_defined_syms.txt
_ULx86_64_get_reg
_ULx86_64_init_local
_ULx86_64_step
_Unwind_Resume
_Ux86_64_getcontext

So, I'd expect libgoogle-perftools-dev to depend on libunwind8-dev, but there's no such dependency:

$ apt-cache depends libgoogle-perftools-dev=2.0-3ubuntu1
libgoogle-perftools-dev
  Depends: libgoogle-perftools4
  Depends: libtcmalloc-minimal4
  Conflicts: libgoogle-perftools-dev:i386

Is this intentional or is this really a missing dependency?