Build fail: aarch64-musl

[DirectorX]

error[E0425]: cannot find value `MAP_32BIT` in crate `libc`

https://github.com/void-linux/void-packages/runs/1754525587?check_suite_focus=true

[Luminarys]

Looks like an issue in nix, I'll take a look

[DirectorX]

Thanks, for now I’ve disabled the build for aarch64-musl

[n8henrie]

Current master fails on aarch64-unknown-linux-musl due to dependency on https://github.com/andrewjstone/amy==0.10.0 (latest), which depends on nix==0.10.0. Looks like this was fixed in nix==0.12; simply patching amy to update to 0.12 allows synapse to compile on aarch64-unknown-linux-musl.

I've submitted a PR to amy, but given that the last commit was in 2018 I'm not sure if it will be merged in a timely fashion or at all. If merged I'll happily make a PR here.

In the meantime, anybody in a rush can patch with my fork (whose only change is to update nix as described)

$ cargo build --all \
    --target aarch64-unknown-linux-musl \
    --config 'target.aarch64-unknown-linux-musl.linker="rust-lld"' \
    --config 'patch.crates-io.amy.git = "https://github.com/n8henrie/amy"' \
    --config 'patch.crates-io.amy.branch = "patch-1"'

relevant links

• Fails to build for aarch64-unknown-linux-musl nix-rust/nix#951
• Update to >=0.12 to allow compilation on aarch64-unknown-linux-musl andrewjstone/amy#36