Can no longer compile upstream lr-flycast

[ChaosEffect]

Hello,

Here is my hardware/software setup:

Pi Model or other hardware: Pi 4B
Power Supply used: Smraza 2.5A
RetroPie Version Used: RetroPie-Setup commit 51a035d9c5d84accfe272a2a12b8eddf1636c0a9
Built From: Pre-made SD Image on RetroPie website
USB Devices connected: Wireless keyboard/mouse combo, X-input wired controller
Controller used: 8BitDo wired X-input controller
Emulator: lr-flycast (upstream)

I have been using both the /libretro/flycast version of lr-flycast and the upstream lr-flycast housed at /flyinghead/flycast as separate emulators on my system for quite some time now. I never experienced the major issues that plagued many users on Raspberry Pi with upstream lr-flycast and resulted in RetroPie going back to the /libretro repo.

I have been using this installation script to update upstream lr-flycast and haven't had any issues until recently.

Now, I get the errors listed in this pastebin link when I try to update. I reached out to flyinghead, who said that I might either need to update GCC or compile with -O2 instead of -O3. Is this something I can somehow safely do on my Raspberry Pi? I'm just not sure how to go about it. I do realize that this version of the emulator is not officially supported, but the thought of trying out a few newly supported games is enticing :)

EDIT: I realized that I posted a slightly older version of the log. I did update the Retropie-Setup script to the commit I mentioned above and tried again, but I got the same errors.

[mitu]

Yes, the upstream flycast will not build on the gcc version from buster since Dec last year. Lowering the optimization level doesn't work, I've already tried that.
Unless the ICE is fixed otherwise, the only solution is a newer gcc, though I haven't tried using clang instead.

[ChaosEffect]

@mitu Thank you for looking into it. If a newer gcc is indeed the only solution, does that mean that bullseye would be needed and buster is out of the question?