Module zlib cannot be read

[Joseph Rushton Wakeling]

Hello all,

I currently have a self-compiled and installed dmd, druntime, phobos and rdmd on 
Ubuntu 12.04.  I get the following error message whenever I try to use rdmd or 
equivalently dmd -run:

  /usr/local/include/d2/std/zlib.d(26): Error: module zlib is in file 
'etc/c/zlib.d' which cannot be read
  import path[0] = /usr/local/include/d2/

Is this just a plain old bug in dev Phobos?  Or is there something wrong with my 
setup (& if so, can anyone advise what it could be)?

Thanks & best wishes,

    -- Joe