Title: binutils 2.28 breaks dmd shared objects
Author: Marco Leise <marco.leise@gmx.de>
Content-Type: text/plain
Posted: 2017-07-06
Revision: 1
News-Item-Format: 2.0
Display-If-Installed: dev-lang/dmd

We currently have two issues with the linkers in binutils. Since 2.27,
the gold linker refuses to work with dmd, but that can be worked around
by using ld.bfd (which is the default).

Now with binutils 2.28 we face a new issue. The way the druntime scans
shared libraries for modules got broken and you see error messages of
the form:

# Fatal Error while loading '/usr/lib/libphobos2.so.XX':
#     The module '<...>' is already defined in '<...>'

The bug report about that was first opened in May and as of now the
answer is to compile all code with '-fPIC'.

# https://issues.dlang.org/show_bug.cgi?id=17375

For you reading this, there are three options to get there:

1. Append '-fPIC' to the DFLAGS of the DMD versions you need to work
   with binutils 2.28. If you only have one, it is in /etc/dmd.conf, if
   you have multiple versions installed pick them from /etc/dmd/.
2. Have the ebuilds append the flags during a reinstall of DMD.
   a) Using the 'selfhost' USE-flag.
   b) By first reinstalling DMD 2.067 (the last C++ based version) and
      then using that to compile one of the later (self-hosting)
      versions.
3. Install binutils 2.27, use
   # sudo binutils-config x86_64-pc-linux-gnu-2.27
   to activate it, reinstall DMD, then switch back to binutils 2.28.