By default, newer GCC versions do not create correct binaries for ARMv6. Even though you pass the correct -mcpu= flag to gcc, it will create startup code for the newer ARMv7 architecture. Running them on your RasPI Zero will cause an "Illegal Instruction" exception.
I don't doubt this was a problem when this toolchain was created, but I can't find such a problem in GCC's Bugzilla. Would this not be considered a bug? And if it is, could it have been fixed by now?
I also don't have a Pi Zero handy to verify this claim myself. I just know that I'm able to build just fine with the basic cross-build tools available on Debian, but I'm also building for a Pi4 which isn't the primary target of this toolchain.
If I can build without this, why am I complaining? Because I'm also required to build with this toolchain and ensuring compatibility has been a source of constant sorrow.
README states
I don't doubt this was a problem when this toolchain was created, but I can't find such a problem in GCC's Bugzilla. Would this not be considered a bug? And if it is, could it have been fixed by now? I also don't have a Pi Zero handy to verify this claim myself. I just know that I'm able to build just fine with the basic cross-build tools available on Debian, but I'm also building for a Pi4 which isn't the primary target of this toolchain.
If I can build without this, why am I complaining? Because I'm also required to build with this toolchain and ensuring compatibility has been a source of constant sorrow.