GLIBC not found while building against Amazon Linux 2 - x86_64

[fancywriter]

Hello!

I am trying to build example from README. It is said it's recommended to use Amazon Linux 2 runtime because it's "easier to build", that's what I am trying to do.

My Cargo.toml:

[package]
name = "rust-lambda-hello"
version = "0.1.0"
edition = "2018"

[dependencies]
lambda_runtime = "0.5.1"
serde_json = "1.0.79"
tokio = { version = "1.17.0", features = [ "macros" ] }

src/main.rs is the same as in README.

Building with command (from the Linux laptop with the same x86_64 architecture, uname -m gives me x86_64)

cargo lambda build --release --target x86_64-unknown-linux-gnu --output-format zip

Success. Than deploying with command

aws lambda create-function --function-name rust-lambda-hello --handler bootstrap --zip-file fileb://./target/lambda/rust-lambda-hello/bootstrap.zip --role <MY_LAMBDA_ROLE_ID> --runtime provided.al2  --environment Variables={RUST_BACKTRACE=1}   --tracing-config Mode=Active

Also success.

But later when I am trying to invoke this function

aws lambda invoke  --function-name rust-lambda-hello --payload '{"hello": "world"}'  --cli-binary-format raw-in-base64-out   output.txt

, it doesn't work, it gives

{
  "errorMessage": "RequestId: <???> Error: Runtime exited with error: exit status 1",
  "errorType": "Runtime.ExitError"
}

When trying to search some logs, I found three lines

/var/task/bootstrap: /lib64/libc.so.6: version `GLIBC_2.28' not found (required by /var/task/bootstrap)
/var/task/bootstrap: /lib64/libc.so.6: version `GLIBC_2.33' not found (required by /var/task/bootstrap)
/var/task/bootstrap: /lib64/libc.so.6: version `GLIBC_2.32' not found (required by /var/task/bootstrap)

I am using rust-1.59.0.

What did I do wrong?

[calavera]

I think you've bumped into this issue: ziglang/zig#9485

I'm trying to find a way to mitigate that. @messense documented that as one of the caveats of using Zig: https://github.com/messense/cargo-zigbuild#caveats

[messense]

@calavera I think the problem is that cargo-lambda disables zig linker when compiling from x86_64 to x86_64: https://github.com/cargo-lambda/cargo-lambda/blob/b9b6a1993ad7ae5563d8c1a82b023396bfaf2a31/crates/cargo-lambda-build/src/lib.rs#L72

[calavera]

oh yeah, you might be right. And the problem is that if we don't disable it, you need to use a nightly build, is that still the case @messense?

If the --target argument is the same as the host target, for example when compiling from Linux x86_64 to Linux x86_64, Cargo by default also uses zig as linker for build dependencies like build scripts and proc-macros which might not work (See rust-cross/cargo-zigbuild#4). You need to use the nightly Rust compiler then cargo-zigbuild will enable the unstable target-applies-to-host option automatically to make it work out of the box.

[messense]

@calavera I'm working on a hack to enable that feature on stable Rust: rust-cross/cargo-zigbuild#32

[messense]

@calavera I'm working on a hack to enable that feature on stable Rust: messense/cargo-zigbuild#32

Released in v0.8.5.

[calavera]

Thanks @messense I'll test it today.

@fancywriter, as a "workaround" until I release a new version of cargo-lambda, you can also build and deploy using ARM as the architecture if your code is not dependent on X86_64 in any way.

1. Change the target when you build the function:

cargo lambda build --release --target aarch64-unknown-linux-gnu --output-format zip

2. Add the --architectures flag in the aws cli:

aws lambda create-function --function-name rust-lambda-hello \
  --handler bootstrap --zip-file fileb://./target/lambda/rust-lambda-hello/bootstrap.zip \
  --role <MY_LAMBDA_ROLE_ID> --runtime provided.al2  \
  --environment Variables={RUST_BACKTRACE=1} \
  --tracing-config Mode=Active \
  --architectures arm64

[calavera]

I just published cargo-lambda 0.7 that mitigates this problem.