On Mon, 2022-05-09 at 20:53 -0400, Dennis Clarke via Gcc-help wrote: > So that sort of looks the same but also I am not sure what is needed > here. As usual the package libc6-dev provides : > > /usr/include/arm-linux-gnueabihf/bits/libc-header-start.h > > However that is in a weird place. Do I need host/target/foobar etc? Generally multiarch directory names are encoded in gcc/config/{arch}/t- linux* files and they have not to be exactly same as --target. Try: /opt/bw/build/gcc-12.1.0_debian_10_armv7l_imed.004/./gcc/xgcc -print-multiarch This command will print the multiarch directory name. And you can compare it with "arm-linux-gnueabihf" to see what's happening. (The OP's mail server doesn't like me, hope he can see the thread via list or someone can forward me.) -- Xi Ruoyao <xry111@xxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University