Hey Ludo’, Amazing, more than a decade of close working with these tools and I never knew about C_INCLUDE_PATH et al! It looks like those will solve a huge portion of the problem. Will look at your gcc and clang patches as well, thank you! ~Shea Ludovic Courtès writes: > Hi Shea, > > Shea Levy skribis: > >> Unlike the traditional approach of installing system libraries into one >> central location like /usr/{lib,include}, the nix package manager [1] >> installs each package into it's own prefix >> (e.g. /nix/store/mn9kqag3d24v6q41x747zd7n5qnalch7-zlib-1.2.8-dev). Moreover, >> each package is built in its own environment determined from its >> explicitly listed dependencies, regardless of what else is installed on >> the system. Because not all package build scripts properly respect >> CFLAGS etc., we currently wrap the compiler [2] to respect custom >> environment variables like NIX_CFLAGS_COMPILE, so during the build of a >> package that depends on zlib and Xlib might have NIX_CFLAGS_COMPILE set >> to "-isystem /nix/store/bl0rz2xinsm9yslghd7n5vaba86zxknh-libX11-1.6.3-dev/include -isystem /nix/store/mn9kqag3d24v6q41x747zd7n5qnalch7-zlib-1.2.8-dev/include". >> >> Unfortunately, as you can see if you click through the link or look >> through the git history, the wrapper is quite complex (frankly, hacky) > >> [2]: https://github.com/NixOS/nixpkgs/blob/8cbdd9d0c290e294a9d783c8868e738db05c9ce2/pkgs/build-support/cc-wrapper/cc-wrapper.sh > > Guix avoids the compiler wrapper altogether like this: > > • We use C_INCLUDE_PATH, LIBRARY_PATH, and friends: > . > > • We have a simple linker wrapper aimed at adding -Wl,-rpath flags: > . > The comment in that file explains why the other options considered > were unsuitable. > > • We modify the built-in “lib” spec of GCC to add the necessary -L and > -rpath flags: > . > > • Likewise, we tell Clang where to find libc and friends: > > . > > This is not too intrusive and more robust than wrapping everything. > > I suppose GCC and Clang could facilitate this by providing configure > options to augment the “lib” spec, specify the location of libc alone, > or something along these lines. > > Thoughts? > > Ludo’.