Is it possible to avoid installing the latest nightly, given that the user already has a nightly rustc?

[ice1000]

https://github.com/dimensionhq/fleet/blob/974d781cc4b09a6617cc7bebedb22dbb48984cf7/installer/src/main.rs#L22

This code just updated my nightly rustc, while I already have a nightly rustc at a specific day. Is it possible to reuse the existing nightly rustc if there is one?

[ice1000]

info: default toolchain set to 'nightly-x86_64-unknown-linux-gnu'

  nightly-x86_64-unknown-linux-gnu installed - rustc 1.64.0-nightly (d68e7ebc3 2022-07-20)

info: note that the toolchain 'nightly-2022-07-18-x86_64-unknown-linux-gnu' is currently in use (overridden by '/home/ice/git-repos/risingwave/rust-toolchain')
Switched to nightly compiler

[VarunPotti]

Will look into this