Hi all, I'm trying to update a Nix derivation for GCC so that I can easily and reliably get a cross compiler for OS development work. In the process of doing this, I seem to have run into a bit of a roadblock just trying to get GCC to compile. I'm more-or-less following a guide: https://wiki.osdev.org/GCC_Cross-Compiler My configuration options end up being just slightly different: --prefix=/nix/store/2qgwg29px8ikpcdy6cn6b66ddxymc1aw-i686-elf-stage-final-gcc-debug-7.4.0 --disable-nls --enable-languages=c\,c++ --without-headers --build=x86_64-unknown-linux-gnu --host=x86_64-unknown-linux-gnu --target=i686-elf I don't think this minor difference should matter. But when I try to compile, I get an error while configuring libgcc. It claims the preprocessor isn't sane. Full error and config.log at https://gist.github.com/Reilithion/02126ee9259d81a54f157e93b3f657d7 I'm no compiler engineer, but it looks to me like the configure script is using methods for making judgments about the capabilities of the compiler and preprocessor that will give inaccurate results in case the target system does not have system headers. And since Nix doesn't keep its system headers for the host in /usr/include there's no "wrong" headers to fall back on. I don't want to be presumptuous, so I invite helpful feedback. But is this a bug in the configure script? - Lucas
