Setup: I have Camble's Safe Shutdown, an Adafruit Powerboost 1000C, and an ADS1015 for the battery monitor. I'm running my buttons through the GPIO with Retrogame. This is basically what my setup looks like: viewtopic.php?f=42&t=4585&start=130#p67718 but with the adafruit PB and i also have a tactile switch to gpio 7 for the battery monitor button.
With just Retrogame installed, it works fine and picks up the buttons great. As soon as I install the Minty Combo script, Retrogame seems to stop working (no buttons register) until I comment out the Minty script call in rc.local again. I never get the battery indicator to show up. I do see an error early on the Minty install that says "libsdl1.2-dev" install failed due to dependency "libcaca-dev" but I cannot seem to do anything about that. Manual install for that lib gives the same message, and manually installing the depencies said they were up-to-date.
When it has "worked" it triggers the same process as if I selected "shut down system" in EmulationStation, which goes through shutting all the services off, and then calls a "shutdown", but then that's where it gets weird again - It throws a bunch of errors around "Kernel Panic" and doesn't shut the pi off. I found that I could add "kernel_panic=1" to /etc/sysctl.conf which makes it do a reboot when that occurs, and then after that reboot starts up, it actually does shut off. But that doesn't seem like the correct functionality (is it?).
I've tried on multiple fresh, new RetroPie installs, and also gave Tinkerboy's image a try, but didn't have any different results there.
Also - for some reason the wifi in the Pi0 i'm using in the build doesnt work, but everything else seems fine, so whenever I need to ssh in or download/update anything, I have to pull the card out and use a different pi0 to do that. I don't know if that could be messing with something, but it didn't seem likely. They are both the same model pi.