Well, yeah. I would figure they would compile fine on other's. There's obviously something wrong with my system. I was just hoping someone could possibly point out what it might be.
On a side note, you have a lot of USE variables.
Edit: I replied before your further comment. I have the ABI's defined in my package.use for multi-lib: https://pastebin.com/2peEzBfF
# eselect python list
Available Python interpreters, in order of preference:
 python2.7 (fallback)
I have it currently set to python 3.4, but that was due to not being able to install pip with python 3.5, so I couldn't get a required lib I needed for development. I just switched it back. Same behavior.
I did rely on my profile to set the proper optimizations, since my CPU family is selected, however I went ahead and added the CPU flags just now.
This should probably be added to the documentation. The top result on google was for old news that was no longer accurate.
cpuinfo2cpuflags is now called cpuid2cpuflags in portage.
to run it you need to call cpuinfo2cpuflags-x86
And it seems setting it to python 3.5 breaks my epro, since it hasn't fully emerged everything yet. Set it back...
# epro list
=== flavor: ===
core, desktop, hardened, minimal, server, workstation*
=== build: ===
current, experimental, (stable*)
=== arch: ===
arm-32bit, arm-64bit, pure64, x86-32bit, (x86-64bit*)
=== subarch: ===
amd64-bulldozer, amd64-excavator, amd64-jaguar, amd64-k10
amd64-k8, amd64-k8+sse3, amd64-piledriver, amd64-steamroller
atom_64, btver1_64, core-avx-i, core2_64, corei7, generic_64
intel64-broadwell, intel64-haswell, intel64-ivybridge, intel64-nehalem
intel64-sandybridge*, intel64-silvermont, intel64-westmere
native_64, nocona, opteron_64, xen-pentium4+sse3_64
=== mix-ins: ===
X, audio, cinnamon, console-extras, dvd, gfxcard-intel-glamor
gnome, gnome-3.16-fixups, hardened, kde, kde-plasma-5, lxde
lxqt, mate, media, media-pro*, mediadevice-audio-consumer, mediadevice-audio-pro
mediadevice-base, mediadevice-video-consumer, mediadevice-video-pro
mediaformat-audio-common, mediaformat-audio-extra*, mediaformat-gfx-common
mediaformat-gfx-extra*, mediaformat-video-common, mediaformat-video-extra*
no-emul-linux-x86, no-systemd, openvz-host, print*, python3-only
selinux, vmware-guest, xfce*