I am no multi-thread compilation expert, but here's what I've got on my system with x11-libs/wxGTK-2.8.12.1-r1 building without any trouble.
On Sat, Jul 26, 2014 at 9:59 PM, Alexander Kapshuk <alexander.kapshuk@gmail.com> wrote:
Forgot to mention.
equery -q b /usr/include/wx-2.8/wx/thread.h
x11-libs/wxGTK-2.8.12.1-r1
Ok so the file IS provided by the package itself, and therefore I see why -l1 makes sense.