Fails to build because of typedef redefinitions. Upstream already fixed the bug in 2.1.1, see bump request for 2.1.1. Attached patch #undef's a compatibility layer but only for gcc >= 4.3.0 ( 2.1.1 removes it entirely, so its probably safe to do).
Created attachment 141031 [details, diff]
gcc-4.3.0 fix for libsigc++-2.0.18
see also bug #203931.
Hum, forgot to close this one too. libsigc++ is in Gnome overlay, and shortly to package.mask.
(In reply to comment #3)
> Hum, forgot to close this one too. libsigc++ is in Gnome overlay, and shortly
> to package.mask.
I'm attempting to build the LiveDVD with gcc-4.3 and dev-libs/libsigc++ fails (obviously). It is not clear where I can find the "fixed" version of this package (the gnome overlay only seems to have ~2.1.1 and ~2.2.2 versions, not 2.0.18-r? )
2.1.x and 2.2.x are not slotted with 2.0.18, they replace it, so just use either of those.
2.2.2 is on my list of gnome-mm stabilization. Please try whatever package you need with that version of libsigc++. If it breaks, please file a bug.
Why has 2.0.18 not been patched?
Because 2.2.2 is stable on most arches, and is asked for stabilization on the remaining arches.
Please update to 2.2.2