Thanks for this! Is this perhaps indicative of missing bindings in the libc crate though? Presumably uclibc has support for these functions?

Ok! In that case this seems fine for now and it can always be updated later if necessary.

Just fyi. The dl_iterate_phdr is present in the latest uclibc release here and added in this commit. As such, I've managed to create a pull request for libc to include dl_iterate_phdr for uclibc here. I'm not sure if that changes anything with respect to this pull request, I just thought it might be relevant.

ok, that implies I will need to upgrade our uClibc version in our toolchain/env, nightmares ahead... but I understand. Thanks

If just having the dl_iterate_phdr binding present in libc will not affect your code, then maybe you don't need to change. If backtrace-rs can work without dl_iterate_phdr, then you're probably all set and don't need to make any more changes. You can check whether this is true by building your rust compiler with the latest libc. Try using the latest libc by adding this patch libc = { git = 'https://github.com/rust-lang/libc.git' } in your rust compiler's working directory Cargo.toml, in the section [patch.crates-io]. Build the rust compiler and test your project in your environment and see what happens. If all is well then you don't need to upgrade just yet.