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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"build error: unable to find library -latomic (llvm/compiler-rt)","articleBody":"### Version\n\nb949c28b7957f913bfbf042e6b07a22af59f1f3f\n\n### Platform\n\n```text\nLinux aarch64-unknown-linux-musl 7.2.3-gentoo-dist-hardened #1 SMP PREEMPT_DYNAMIC Sat Sep  5 05:15:30 CEST 2026 aarch64 GNU/Linux\n\nllvm stack (clang, libcxx, compiler-rt, libunwind)\n```\n\n### Subsystem\n\n_No response_\n\n### What steps will reproduce the bug?\n\n```\n$ ./configure\n$ make\n```\n\n### How often does it reproduce? Is there a required condition?\n\nalways\n\n### What is the expected behavior? Why is that the expected behavior?\n\nbuild succeeds\n\n### What do you see instead?\n\n```bash\nld.lld: error: unable to find library -latomic\nclang++: error: linker command failed with exit code 1 (use -v to see invocation)\nmake[1]: *** [node_js2c.target.mk:144: /home/pepper/dev/ghrepos/node/out/Release/node_js2c] Error 1\nmake: *** [Makefile:145: node] Error 2\n```\n\n### Additional information\n\n\n\nThis [comment in tools/v8_gypfiles/v8.gyp](https://github.com/peppergrayxyz/node/blob/b949c28b7957f913bfbf042e6b07a22af59f1f3f/tools/v8_gypfiles/v8.gyp#L1404-L1407) suggests, that `-latomic` was added to facilitate the use of atomic operations as described in the linked clang docs:\n```gyp\n# Platforms that don't have Compare-And-Swap (CAS) support need to link atomic library\n# to implement atomic memory access.\n# Clang needs it for some atomic operations (https://clang.llvm.org/docs/Toolchain.html#atomics-library).\n ['(OS==\"linux\" and clang==1) or (v8_current_cpu in [\"mips64\", \"mips64el\", \"arm\", \"riscv64\", \"loong64\"])', {\n```\n\nBut the docs also state that `compiler-rt` (LLVM) **or** `libatomic` (GNU) may be used. `-latomic` requests `libatomic` while atomics from `compiler-rt` can be used without linker settings.\n\n**Current behaviour** \nThe builds adds `-latomic` which unconditionally requests to link `libatomic` even in cases when it is not needed or desired.\n\n**Desired behaviour**\nCheck if `-latomic` is needed e.g. like mesa [meson.build](https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/meson.build?ref_type=heads#L1639), which checks if atomics compile successfully without link settings (which is the case with  `compiler-rt`). Then append them conditionally only when needed.","author":{"url":"https://github.com/peppergrayxyz","@type":"Person","name":"peppergrayxyz"},"datePublished":"2026-09-08T02:45:30Z","url":"https://github.com/nodejs/node/issues/65900"}