from https://github.com/rubygems/rubygems/commit/bfb0ae69776069155d2092702bfbb5a12617d85a

Previously if `~/.bundle/cache/compact_index/rubygems.org.*/version`
were owned by root with read-only access, `bundle install` would fail
with a misleading error message. For example:

```
There was an error while trying to write to `/tmp/bundler-compact-index-20220711-1823-npllre/versions`. It is
likely that you need to grant write permissions for that path.
```

This happened because the EACCESS error was caught by
`SharedHelpers.filesystem_access`, which makes it look like the target
directory is at fault instead of the source.

We can't simply drop this guard because that causes the opposite
problem: the permission error appears to come from the source instead of
the target, since `CompactIndexClient::Cache#lines` also wraps read
access errors.

Instead, bring a minimal implementation of `FileUtils.cp` and nest calls
to `SharedHelpers.filesystem_access` properly.

https://github.com/rubygems/rubygems/commit/320822c070

Co-authored-by: Stan Hu <stanhu@gmail.com>

  Picked at 12aeef6ba9a3be0022be9934c1a3e4c46a03ed3a

This block of code already wraps file operations with
`SharedHelpers.filesystem_access`, which rescues and re-raises more
friendly errors. Also, I'm not fully sure creating a temporary directory
can end up raising an `Errno::EACCES` error from reading `tmpdir`
sources. Finally, this rescue block apparently leads to some false
positives when firewall is blocking the ruby executable on Windows, or
at least that's what we've got reported.

In any case, I think it's best to let the original error be raised.

https://github.com/rubygems/rubygems/commit/f7dbe54404