The latest version of perf in portage is 2.6.35_rc4. Please bump it to the version that comes with the current kenrel (2.6.36). Reproducible: Always
I've just renamed the ebuild, but one of the problems is that portage sets $ARCH to "amd64" instead of the standard "x86-64", so perf dwarf support doesn't recognize the arch.
Sorry this is mostly my fault because I have stopped using perf — I added it when I needed it and I haven't needed it in a while. As for arch, toolchain-funcs.eclass has a function to do the conversion to the kernel values; on the other hand, perf's buildsystem is a bloody mess and after feeling like I'm talking with a stone I have stopped trying to make sense of it alone.
Any news on this bug? I find perf quite useful so it would be nice to have it updated to newer kernel's version (2.6.39?)
flameeyes stopped using perf so the package is orphaned. I suggest an ebuild that looks at your /usr/src/linux directory and compiles whatever is available in tools/perf. When you upgrade your kernel sources you rebuild that package, like an out of tree kernel module. That might make it easier to maintain.