CI-Examples: Rust test failure was observed due to indexmap version upgrade

[davidtian888]

Description of the problem

Test failure was observed in rust regression test:

---------test log-----
+ cd CI-Examples/rust
+ lsof -t -i:3000
+ export PID=
+ [  !=  ]
+ [ ubuntu22.04 = debian12 ]
+ make -j8
cargo build --release
    Updating crates.io index
 Downloading crates ...
  Downloaded equivalent v1.0.2
  Downloaded futures-channel v0.3.31
  Downloaded http-body v0.4.6
  Downloaded try-lock v0.2.5
  Downloaded tower-service v0.3.3
  Downloaded want v0.3.1
  Downloaded pin-utils v0.1.0
  Downloaded httpdate v1.0.3
  Downloaded fnv v1.0.7
  Downloaded futures-core v0.3.31
  Downloaded cfg-if v1.0.4
  Downloaded futures-task v0.3.31
  Downloaded lock_api v0.4.14
  Downloaded slab v0.4.11
  Downloaded scopeguard v1.2.0
  Downloaded signal-hook-registry v1.4.6
  Downloaded itoa v1.0.15
  Downloaded futures-sink v0.3.31
  Downloaded parking_lot_core v0.9.12
  Downloaded pin-project-lite v0.2.16
  Downloaded httparse v1.10.1
  Downloaded quote v1.0.41
  Downloaded tokio-macros v2.6.0
  Downloaded once_cell v1.21.3
  Downloaded parking_lot v0.12.5
  Downloaded unicode-ident v1.0.20
  Downloaded smallvec v1.15.1
  Downloaded tracing-core v0.1.34
  Downloaded socket2 v0.5.10
  Downloaded socket2 v0.6.1
  Downloaded proc-macro2 v1.0.103
  Downloaded tracing v0.1.41
  Downloaded mio v1.1.0
  Downloaded http v0.2.12
  Downloaded indexmap v2.12.0
  Downloaded bytes v1.10.1
  Downloaded tokio-util v0.7.16
  Downloaded hashbrown v0.16.0
  Downloaded futures-util v0.3.31
  Downloaded h2 v0.3.27
  Downloaded hyper v0.14.32
  Downloaded syn v2.0.108
  Downloaded libc v0.2.177
  Downloaded tokio v1.48.0
error: package `indexmap v2.12.0` cannot be built because it requires rustc 1.82 or newer, while the currently active rustc version is 1.75.0
Either upgrade to rustc 1.82 or newer, or use
cargo update indexmap@2.12.0 --precise ver
where `ver` is the latest version of `indexmap` supporting rustc 1.75.0
make: *** [Makefile:26: target/release/rust-hyper-http-server] Error 101

Steps to reproduce

No response

Expected results

No response

Actual results

No response

Gramine commit hash

ff71d7a

[kailun-qin]

error: package indexmap v2.12.0 cannot be built because it requires rustc 1.82 or newer, while the currently active rustc version is 1.75.0

Have you tried using the latest stable Rust toolchain (Rust compiler)?

Note that it's required for this example anyway, pls see:

gramine/CI-Examples/rust/README.md

Lines 15 to 18 in ff71d7a

	NOTE: The Tokio crate is known to require sufficiently new Rust compiler
	(`rustc`). Such new version may not be installed by the OS distro Rust package.
	In such case, please install the latest stable Rust compiler manually, e.g., via
	https://rustup.rs/.