Repository navigation
v1.28.0 broke rustup show active-toolchain #4217
Description
Activity
I also came across
Just for clarity: the previous output of
rustup show active-toolchainwas:stable-x86_64-pc-windows-msvc (default)Note the brackets at the end. So something like
cargo +$(rustup show active-toolchain) foowouldn't have worked (and this specific instance isn't useful, as it sets the active toolchain to the active toolchain.)The intention was to make it easier to parse in scripts, because you can split on the newline to get the toolchain name, while also making the reason-for-active much more intuitive.
I'm not sure what Rust Rover was doing, but breaking it probably isn't good. Perhaps they were cutting out the brackets directly.
Reacted by SkyReacted by Teoh Han HuiFWIW this change also broke some logic in miri-test-libstd (that I already fixed by now), where it was using this rune to get the toolchain name:
rustup show active-toolchain | cut -f 1 -d' 'I have now changed this to
rustup show active-toolchain | head -n1 | cut -f 1 -d' 'The newline indeed makes it easier to parse, but unfortunately throws off existing parsers... so yeah the revert is probably a good idea. Would be nice to clean this up eventually, but that seems non-trivial.
Problem
IntelliJ RustRover and scripts use
rustup show active-toolchainto get the active toolchain name. The output is now broken as it includes a message "active because: it's the default toolchain" on a second line.This happened in #3225.
Which is why it should output exactly the toolchain name, nothing more.
Steps
Current output (v1.28.0):
Gives this chaotic error when loading any project in RustRover:
It is trying to find a toolchain with the name
nightly-x86_64-unknown-linux-gnu\nactive because: it's the default toolchain(with a newline in the middle) which obviously doesn't exist.Previous output (v1.27.1 and below):
Possible Solution(s)
A
v1.28.1should be released with a patch reverting just therustup show active-toolchainoutput back to pre-1.28.0 behavior.Rustup version
rustup 1.28.0 (6e19fbec7 2025-03-02)cc @majaha @rami3l @rust-lang/rustup