From: merch-redmine@...
Date: 2020-10-22T15:05:32+00:00
Subject: [ruby-core:100506] [Ruby master Bug#17254] ENV.replace may set nil instead of the proper value

Issue #17254 has been updated by jeremyevans0 (Jeremy Evans).


znz (Kazuhiro NISHIYAMA) wrote in #note-2:
> I dump duplicated keys with encoding.
> Encodings of duplicated keys are same.

Interesting. So it may be that duplicate keys in ENV in general are in issue?  We generally think of ENV having unique keys, but I'm guessing that is not enforced by the kernel.

Looking at the implementation of setenv(3)/unsetenv(3) on OpenBSD, it does specify that that there can be multiple environment entries with the same key, so Ruby's ENV implementation should probably not assume there is at most one entry per key.

----------------------------------------
Bug #17254: ENV.replace may set nil instead of the proper value
https://bugs.ruby-lang.org/issues/17254#change-88128

* Author: znz (Kazuhiro NISHIYAMA)
* Status: Open
* Priority: Normal
* ruby -v: ruby 2.7.2p137 (2020-10-01 revision 5445e04352) [x86_64-linux]
* Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN
----------------------------------------
On docs.ruby-lang.org, it uses [snap ruby](https://snapcraft.io/ruby), and it failed to run `rdoc`.

```
Oct 07 13:20:08 docs-2020.ruby-lang.org env[6183]: rdoc --title Documentation for Ruby master --main README.md --output /var/www/docs.ruby-lang.org/releases/20200916140300/master -U --all --encoding=UTF-8 .
Oct 07 13:20:08 docs-2020.ruby-lang.org env[6183]: <internal:gem_prelude>:1:in `require': cannot load such file -- rubygems.rb (LoadError)
Oct 07 13:20:08 docs-2020.ruby-lang.org env[6183]:         from <internal:gem_prelude>:1:in `<internal:gem_prelude>'
Oct 07 13:20:08 docs-2020.ruby-lang.org env[6183]: rake aborted!
```

I investigate it, it caused by setting nil instead of the proper value in `ENV.replace`.

```
vagrant@buster:/tmp/t$ cat Gemfile
# frozen_string_literal: true

source "https://rubygems.org"

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

# gem "rails"
vagrant@buster:/tmp/t$ env PATH=/var/www/docs.ruby-lang.org/shared/bundle/ruby/2.7.0/bin:/snap/bin:$PATH DEBIAN_DISABLE_RUBYGEMS_INTEGRATION=1 bundle exec env -u RUBYOPT ruby -r/snap/ruby/189/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/setup -e 'p ENV["RUBYLIB"]'
"/snap/ruby/189/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib"
```

Calling `ENV.clear` before `ENV.replace` resolves this issue.

```
vagrant@buster:/tmp/t$ cat /tmp/clear-before-replace.rb
class << ENV
  alias orig_replace replace
  def replace(h)
    clear
    orig_replace(h)
  end
end
vagrant@buster:/tmp/t$ env PATH=/var/www/docs.ruby-lang.org/shared/bundle/ruby/2.7.0/bin:/snap/bin:$PATH DEBIAN_DISABLE_RUBYGEMS_INTEGRATION=1 bundle exec env -u RUBYOPT ruby -r/tmp/clear-before-replace -r/snap/ruby/189/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib/bundler/setup -e 'p ENV["RUBYLIB"]'
"/snap/ruby/189/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/lib:/snap/ruby/189/lib/ruby/2.7.0:/snap/ruby/189/lib/ruby/2.7.0/amd64"
```

Where should call `ENV.clear`?
In `ENV.replace` or caller of `ENV.replace`?


---Files--------------------------------
full-env-log.txt (8.96 KB)
rdoc-failed-log.txt (2.57 KB)


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