rustup-init fails to copy itself to CARGO_HOME with OS error 11 (EAGAIN)

Problem

I'm running into an install issue where the downloaded rustup-init binary fails to copy itself into CARGO_HOME :

> env RUSTUP_HOME=/tmp/rustup CARGO_HOME=/tmp/rustup/Cargo /tmp/rustup-install.sh  --profile minimal --no-modify-path -y
info: downloading installer
warning: it looks like you have an existing installation of Rust at:
warning: /usr/bin
warning: rustup should not be installed alongside Rust. Please uninstall your existing Rust first.
warning: Otherwise you may have confusion unless you are careful with your PATH
warning: If you are sure that you want both rustup and your already installed Rust
warning: then please reply `y' or `yes' or set RUSTUP_INIT_SKIP_PATH_CHECK to yes
warning: or pass `-y' to ignore all ignorable checks.
error: cannot install while Rust is installed
warning: continuing (because the -y flag is set and the error is ignorable)
error: could not copy file from '/tmp/tmp.xxJfK1RrCn/rustup-init' to '/tmp/rustup/Cargo/bin/rustup': Resource temporarily unavailable (os error 11)

Steps

1. (optional) download the install script from rustup.rs and save it
2. execute it as shown above

Possible Solution(s)

I think the failing copy operation must be using sendfile(2) behind the scenes because this function is apparent problematic on Linux when the destination is on a ZFS pool (I'm running ZFS 2.1.2). Indeed, the issue doesn't arise when I point RUSTUP_HOME and CARGO_HOME to a tmpfs volume.

My current workaround has been to download the correct rustup-init binary myself, move it to /desired/location/rustup and then figure out how to invoke it to obtain the install I was after (stable/minimal). Fortunately this is possible without further EAGAIN errors.

Notes

No response

Rustup version

rustup 1.25.2 (17db695f1 2023-02-01)

Installed toolchains

N/A because the error occurs before anything else gets installed.

No source files or tests are named. Reproduce the installer command with CARGO_HOME and RUSTUP_HOME on ZFS and tmpfs, then trace the copy of rustup-init into CARGO_HOME/bin/rustup. Done means the installation completes without the EAGAIN copy error on the affected filesystem.