Lets install rust on Debian Stretch!

just-another-log-from-shell-session.out

$ curl https://sh.rustup.rs -sSf | sh
info: downloading installer
error: it looks like you have an existing installation of Rust at:
error: /usr/bin
error: rustup cannot be installed alongside Rust. Please uninstall first
error: if this is what you want, restart the installation with `-y'
error: cannot install while Rust is installed
[ apt remove rustc libstd-rust-1.24 in another shell ]

$ curl https://sh.rustup.rs -sSf | sh
info: downloading installer

Welcome to Rust!

This will download and install the official compiler for the Rust programming 
language, and its package manager, Cargo.

It will add the cargo, rustc, rustup and other commands to Cargo's bin 
directory, located at:

  /home/user/.cargo/bin

This path will then be added to your PATH environment variable by modifying the
profile file located at:

  /home/user/.profile

You can uninstall at any time with rustup self uninstall and these changes will
be reverted.

Current installation options:

   default host triple: x86_64-unknown-linux-gnu
     default toolchain: stable
  modify PATH variable: yes

1) Proceed with installation (default)
2) Customize installation
3) Cancel installation

>
[ hit enter for default]

info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
info: latest update on 2018-09-25, rust version 1.29.1 (b801ae664 2018-09-20)
info: downloading component 'rustc'
 69.7 MiB /  69.7 MiB (100 %)   2.2 MiB/s ETA:   0 s
 info: downloading component 'rust-docs'
  8.2 MiB /   8.2 MiB (100 %)   2.1 MiB/s ETA:   0 s                
info: installing component 'rustc'
info: installing component 'rust-std'
info: installing component 'cargo'
info: installing component 'rust-docs'
info: default toolchain set to 'stable'

  stable installed - rustc 1.29.1 (b801ae664 2018-09-20)


Rust is installed now. Great!

To get started you need Cargo's bin directory ($HOME/.cargo/bin) in your PATH 
environment variable. Next time you log in this will be done automatically.

To configure your current shell run source $HOME/.cargo/env
$ source $HOME/.cargo/env
$ rustc --version
rustc 1.29.1 (b801ae664 2018-09-20)
$ cargo --version
cargo 1.29.0 (524a578d7 2018-08-05)

$ cargo search REPL
    Updating registry `https://github.com/rust-lang/crates.io-index`
repl = "0.7.1"           # Generic REPL trait                                                                                         
lamcal-repl = "0.3.0"    # A lambda calculus command line repl
evcxr_repl = "0.1.2"     # A REPL for Rust
rvs-repl = "0.4.1"       # REPL for Rvs - A library for defining and evaluating random variables using a simple DSL
gluon_repl = "0.9.1"     # REPL for gluon. A static, type inferred programming language for application embedding
gluon = "0.9.1"          # A static, type inferred programming language for application embedding
click = "0.3.2"          # A command-line REPL for Kubernetes that integrates into existing cli workflows
bspl = "1.0.0"           # bspl is a REPL for practising bitwise operations
rie = "0.1.0"            # REPL like interactive code editor
rurust = "0.1.11"        # High level Ruby VM bindings
... and 26 crates more (use --limit N to see more)

$ cargo install evcxr_repl
    Updating registry `https://github.com/rust-lang/crates.io-index`
[etc...]

$ evcxr
Welcome to evcxr. For help, type :help
>> let foo = vec!["f", "00", "b4r"];
>> println!("Situation {:?}!", foo.join(''));
                                         ^ 
character constant must be escaped: '
>> println!("Situation {:?}!", foo.join(""));
Situation "f00b4r"!
>>