On 4 different systems I was only able to include in guicast/Makefile, the CFLAGS += $(-fsanitize=alignment) and set the LDFLAGS environment variable to -fsanitize=alignment in order to compile. But when I ran bin/cin I never got any errors of the type "bctheme.C:458:15: runtime error: load of misaligned address". This was Fedora 32, Ubuntu 16, Debian 32-bit 9.1, and Debian 11.0. I only loaded a file, played a little of it, and added a plugin as a test (maybe there was something in particular I should have tried?)

no, it was right on startup on Slackware 15.0 (mostly) 32-bit over 64-bit kernel....

I'll try on ppc32 machine hopefully soon (ppc/sparc/alpha said to be much more sensitive to such errors)

That was Debian 11.0 32-bit that I tested it on, not 64 bit.

If the patch fixes it for Slackware 15.0 and since it does not seem to add any problems for other distros, we can check it into GIT. I just do not understand the patch at all because I don't know C code and can not tell if the code is better with essentially the same outcome.