Problem
In a new empty edition 2015 project, when running a pre-1.8 toolchain, it prints info: syncing channel updates for '$toolchain' on each build.
Steps
Create a new project, remove edition = "2018" from the Cargo.toml
> for i in {0..7}; do CARGO_HOME=$(pwd) cargo +1.$i.0 run; done
info: syncing channel updates for '1.0.0-x86_64-unknown-linux-gnu'
info: downloading component 'rust'
Running `target/debug/foo`
Hello, world!
Compiling foo v0.1.0 (file:///tmp/tmp.lSHQ5tXJ5P/foo)
info: syncing channel updates for '1.1.0-x86_64-unknown-linux-gnu'
info: downloading component 'rust'
Running `target/debug/foo`
Hello, world!
Compiling foo v0.1.0 (file:///tmp/tmp.lSHQ5tXJ5P/foo)
info: syncing channel updates for '1.2.0-x86_64-unknown-linux-gnu'
info: downloading component 'rust'
Running `target/debug/foo`
Hello, world!
Compiling foo v0.1.0 (file:///tmp/tmp.lSHQ5tXJ5P/foo)
info: syncing channel updates for '1.3.0-x86_64-unknown-linux-gnu'
info: downloading component 'rust'
Running `target/debug/foo`
Hello, world!
Compiling foo v0.1.0 (file:///tmp/tmp.lSHQ5tXJ5P/foo)
info: syncing channel updates for '1.4.0-x86_64-unknown-linux-gnu'
info: downloading component 'rust'
Running `target/debug/foo`
Hello, world!
Compiling foo v0.1.0 (file:///tmp/tmp.lSHQ5tXJ5P/foo)
info: syncing channel updates for '1.5.0-x86_64-unknown-linux-gnu'
info: downloading component 'rust'
Running `target/debug/foo`
Hello, world!
Compiling foo v0.1.0 (file:///tmp/tmp.lSHQ5tXJ5P/foo)
info: syncing channel updates for '1.6.0-x86_64-unknown-linux-gnu'
info: downloading component 'rust'
Running `target/debug/foo`
Hello, world!
Compiling foo v0.1.0 (file:///tmp/tmp.lSHQ5tXJ5P/foo)
info: syncing channel updates for '1.7.0-x86_64-unknown-linux-gnu'
info: downloading component 'rust'
Running `target/debug/foo`
Hello, world!Notes
Output of rustup --version:
rustup 1.24.2 (755e2b07e 2021-05-12)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.54.0-nightly (4e3e6db01 2021-05-18)`
Output of rustup show:
it's a lot 😁
Default host: x86_64-unknown-linux-gnu
rustup home: /home/nemo157/.rustup
installed toolchains
--------------------
stable-x86_64-unknown-linux-gnu
beta-x86_64-unknown-linux-gnu
nightly-2017-01-26-x86_64-unknown-linux-gnu
nightly-2018-03-15-x86_64-unknown-linux-gnu
nightly-2018-03-16-x86_64-unknown-linux-gnu
nightly-2020-03-08-x86_64-unknown-linux-gnu
nightly-2020-03-18-x86_64-unknown-linux-gnu
nightly-2020-03-19-x86_64-unknown-linux-gnu
nightly-2020-03-20-x86_64-unknown-linux-gnu
nightly-2020-04-08-x86_64-unknown-linux-gnu
nightly-2020-06-29-x86_64-unknown-linux-gnu
nightly-2020-07-23-x86_64-unknown-linux-gnu
nightly-2020-07-27-x86_64-unknown-linux-gnu
nightly-2020-10-06-x86_64-unknown-linux-gnu
nightly-2020-10-07-x86_64-unknown-linux-gnu
nightly-2020-11-10-x86_64-unknown-linux-gnu
nightly-2020-11-24-x86_64-unknown-linux-gnu
nightly-2021-01-17-x86_64-unknown-linux-gnu
nightly-2021-04-01-x86_64-unknown-linux-gnu
nightly-2021-04-08-x86_64-unknown-linux-gnu
nightly-2021-04-10-x86_64-unknown-linux-gnu
nightly-2021-04-11-x86_64-unknown-linux-gnu
nightly-2021-04-12-x86_64-unknown-linux-gnu
nightly-2021-04-16-x86_64-unknown-linux-gnu
nightly-2021-04-17-x86_64-unknown-linux-gnu
nightly-2021-04-18-x86_64-unknown-linux-gnu
nightly-2021-04-27-x86_64-unknown-linux-gnu
nightly-2021-05-01-x86_64-unknown-linux-gnu
nightly-x86_64-unknown-linux-gnu
1.10-x86_64-unknown-linux-gnu
1.11-x86_64-unknown-linux-gnu
1.12-x86_64-unknown-linux-gnu
1.13-x86_64-unknown-linux-gnu
1.14-x86_64-unknown-linux-gnu
1.15-x86_64-unknown-linux-gnu
1.16-x86_64-unknown-linux-gnu
1.17-x86_64-unknown-linux-gnu
1.18-x86_64-unknown-linux-gnu
1.19-x86_64-unknown-linux-gnu
1.20-x86_64-unknown-linux-gnu
1.21-x86_64-unknown-linux-gnu
1.22-x86_64-unknown-linux-gnu
1.23-x86_64-unknown-linux-gnu
1.24-x86_64-unknown-linux-gnu
1.25-x86_64-unknown-linux-gnu
1.26-x86_64-unknown-linux-gnu
1.27-x86_64-unknown-linux-gnu
1.28-x86_64-unknown-linux-gnu
1.29-x86_64-unknown-linux-gnu
1.30-x86_64-unknown-linux-gnu
1.31-x86_64-unknown-linux-gnu
1.32-x86_64-unknown-linux-gnu
1.33-x86_64-unknown-linux-gnu
1.34-x86_64-unknown-linux-gnu
1.35-x86_64-unknown-linux-gnu
1.36-x86_64-unknown-linux-gnu
1.37-x86_64-unknown-linux-gnu
1.38-x86_64-unknown-linux-gnu
1.39-x86_64-unknown-linux-gnu
1.40-x86_64-unknown-linux-gnu
1.41-x86_64-unknown-linux-gnu
1.42-x86_64-unknown-linux-gnu
1.43-x86_64-unknown-linux-gnu
1.44-x86_64-unknown-linux-gnu
1.45-x86_64-unknown-linux-gnu
1.46-x86_64-unknown-linux-gnu
1.47-x86_64-unknown-linux-gnu
1.48-x86_64-unknown-linux-gnu
1.51-x86_64-unknown-linux-gnu
1.52-x86_64-unknown-linux-gnu
1.8-x86_64-unknown-linux-gnu
1.9-x86_64-unknown-linux-gnu
62cbe81b8a4bf932ca59c4b75372af50fb4a247c
local
local1
updated
1.0.0-x86_64-unknown-linux-gnu
1.1.0-x86_64-unknown-linux-gnu
1.2.0-x86_64-unknown-linux-gnu
1.3.0-x86_64-unknown-linux-gnu
1.4.0-x86_64-unknown-linux-gnu
1.5.0-x86_64-unknown-linux-gnu
1.6.0-x86_64-unknown-linux-gnu
1.7.0-x86_64-unknown-linux-gnu
1.8.0-x86_64-unknown-linux-gnu
installed targets for active toolchain
--------------------------------------
aarch64-unknown-linux-gnu
thumbv6m-none-eabi
thumbv7m-none-eabi
wasm32-unknown-unknown
wasm32-wasi
x86_64-pc-windows-gnu
x86_64-pc-windows-msvc
x86_64-unknown-linux-gnu
x86_64-unknown-redox
active toolchain
----------------
nightly-x86_64-unknown-linux-gnu (default)
rustc 1.54.0-nightly (4e3e6db01 2021-05-18)
Problem
In a new empty edition 2015 project, when running a pre-1.8 toolchain, it prints
info: syncing channel updates for '$toolchain'on each build.Steps
Create a new project, remove
edition = "2018"from theCargo.tomlNotes
Output of
rustup --version:Output of
rustup show:it's a lot 😁