UnhandledPromiseRejectionWarning on macOS

[eregon]

https://github.com/ruby/spec/pull/683/checks?check_run_id=202172164

Run actions/setup-ruby@v1
  with:
    ruby-version: 2.5.x
do ln -sf /Users/runner/hostedtoolcache/Ruby/2.5.5/x64/bin/ruby /usr/bin/ruby
##[add-path]/Users/runner/hostedtoolcache/Ruby/2.5.5/x64/bin
ln: /usr/bin/ruby: Operation not permitted
(node:825) UnhandledPromiseRejectionWarning: Error: The process 'sudo' failed with exit code 1
    at ExecState._setResult (/Users/runner/runners/2.157.0/work/_actions/actions/setup-ruby/v1/node_modules/@actions/exec/lib/toolrunner.js:547:25)
    at ExecState.CheckComplete (/Users/runner/runners/2.157.0/work/_actions/actions/setup-ruby/v1/node_modules/@actions/exec/lib/toolrunner.js:530:18)
    at ChildProcess.<anonymous> (/Users/runner/runners/2.157.0/work/_actions/actions/setup-ruby/v1/node_modules/@actions/exec/lib/toolrunner.js:430:27)
    at ChildProcess.emit (events.js:200:13)
    at maybeClose (internal/child_process.js:1021:16)
    at Socket.<anonymous> (internal/child_process.js:430:11)
    at Socket.emit (events.js:200:13)
    at Pipe.<anonymous> (net.js:586:12)
(node:825) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:825) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

It seems the ln -sf fails on macOS. The build still works nevertheless.

Actually, what tool requires /usr/bin/ruby to be the same as ruby in PATH?
AFAIK other CIs and all 3 major Ruby managers do not touch /usr/bin/ruby.
I saw

setup-ruby/src/installer.ts

Lines 18 to 20 in 623660d

	// Ruby / Gem heavily use the '#!/usr/bin/ruby' to find ruby, so this task needs to
	// replace that version of ruby so all the correct version of ruby gets selected
	// replace the default

but in my experience there is no such problem with RubyGems (as long as gem is on PATH too alongside ruby, but that should always be the case).

I think if such a workaround is needed, it should be done only in those needed cases, not by setup-ruby, what do you think?

[chrishough]

I am having this same problem, is there a work around?

[eregon]

PR to fix this in #29

[chrishough]

Thank you @eregon

[eregon]

This is still not in @v1 (see #81).
v1 is very old: https://github.com/actions/setup-ruby/tree/v1 = 50f3cc9
Probably v1 should be updated to v1.1.1.

In any case, probably best to use https://github.com/ruby/setup-ruby which is more actively maintained.
cc @alexisbronchart