mirror of
https://github.com/NixOS/nixpkgs.git
synced 2025-02-02 18:23:44 +00:00
01e460d69e
The [(failing-)build log](https://hydra.nixos.org/build/219379873/nixlog/1) has errors that look like: `undefined symbol: __aarch64_cas8_sync`. This led me to find out about the newly-introduced `-moutline-atomics`, which is **on by default** in GCC 10.1 (according to [this blog post](https://community.arm.com/arm-community-blogs/b/tools-software-ides-blog/posts/making-the-most-of-the-arm-architecture-in-gcc-10)) and in Clang 12.0.0 (according to [the release notes](https://releases.llvm.org/12.0.0/tools/clang/docs/ReleaseNotes.html)) Not all ARMv8-A processors support atomic stuff like `__aarch64_cas8_sync`, it's only those that are ARMv8.1-A or later that do. Examples of pre-ARMv8.1-A processors include the Cortex-A72 used in the Raspberry Pi 4 (which is how I discovered this problem (I am running `hydra` on it, which indirectly depends on `HashSharedMem`)), and any older ARMv8-A processors. The problem here is solvable either by linking the compiler runtime library (which I did not try, since I don't know exactly which one to use) *or* by simply not generating outlines for atomic operations. I went with the "easier" path (which was also what was was happening in older versions of GCC, I think) of disabling atomic outlines with `-mno-outline-atomics`, and it works! |
||
|---|---|---|
| .. | ||
| applications | ||
| build-support | ||
| common-updater | ||
| data | ||
| desktops | ||
| development | ||
| games | ||
| misc | ||
| os-specific | ||
| pkgs-lib | ||
| servers | ||
| shells | ||
| stdenv | ||
| test | ||
| tools | ||
| top-level | ||