Flaky has_local in rustup-init.sh

[daniel-pfeiffer]

Verification

• I searched for recent similar issues at https://github.com/rust-lang/rustup/issues?q=is%3Aissue and found no duplicates.
• I am on the latest version of Rustup according to https://github.com/rust-lang/rustup/tags and am still able to reproduce my issue.

Problem

On a system without local, it would continue searching in $PATH. If a such a command were found, that would wrongly be used throughout.

Steps

1. Login to where /bin/sh has no builtin local
2. Create an executable local in $PATH

Possible Solution(s)

I don’t know how portable an empty path is, nor whether prepending it will affect searching for the following command on such a Shell. This should probably work anywhere:

has_local() {
    # shellcheck disable=SC2034  # deliberately unused
    PATH= local _has_local
}

Notes

No response

Rustup version

Reading latest script on GitHub.

Installed toolchains

Irrelevant, since I don’t have a Shell with no builtin `local`

OS version

Irrelevant, since I don’t have a Shell with no builtin `local`

[rami3l]

@daniel-pfeiffer Hello!

I don’t have a Shell with no builtin local

No worries, I have an example! You can try out this snippet below at https://tio.run/#ksh:

has_local() {
    # shellcheck disable=SC2034  # deliberately unused
    local _has_local
}

has_local && echo "has local" || echo "no local"

This will print out "no local".

I don’t know how portable an empty path is, nor whether prepending it will affect searching for the following command on such a Shell.

Your claim looks pretty valid¹, would you mind making a PR for this? Many thanks in advance 🙏

Footnotes

1. For that to work you should also take into account that this fabricated "local" command should also take '_has_local' as a valid input. This is probably why this hasn't been that much of a concern for so long. ↩