Similar to #412, on armv7-unknown-linux-gnueabihf we get symbols __sync_fetch_and_add_4 and __sync_fetch_and_add_8 (and probably others) clashing when a C/C++ tries to link with our library. We've tried on arm-unknown-linux-gnueabihf, aarch64-unknown-linux-gnu and x86_64-unknown-linux-gnu and it doesn't seem to generate these symbols.

On Zulip, Alex Crichton suggested to flag the symbol as weak. This issue is off my level of competence, so I'll probably leave it to someone who knows better than me.

Some links that I've found while investigating this (for cross-reference):

• https://www.mail-archive.com/debian-arm@lists.debian.org/msg21551.html
• Keep codegen units unmerged when building compiler builtins rust#70846 (comment)
• Multiple definitions of atomic builtins on armv5te-unknown-linux-gnu rust#48625
• Add atomic support for pre-ARMv6 on Linux #115