Elfutils likes to directly access /proc/PID et.al. This only works when the
running process is local. For the remote case elfutils needs to call back
accessor methods supplied by the client.
libunwind provides an example of this.
There is no bug here. The simple dwfl hooks that use /proc are for examples and
for simple tools with the -k/-p options. There is a callback API for real
applications using the libraries to use. A real application does not want
elfutils doing that work for it anyway.