Ruby: Gem version 3.11.2 doesn't load on Ruby 2.7

[threeplanetssoftware]

What version of protobuf and what language are you using?
Version: 3.11.2 (released ~December 13, 2019)
Language: Ruby 2.7 (released December 25, 2019)

Windows 8, Linux Ubuntu and Mint

What runtime / compiler are you using (e.g., python version or gcc version)
Ruby 2.7

What did you do?
Steps to reproduce the behavior:

1. gem install google-protobuf
2. Run any Ruby code which has require 'google-protobuf' at the start
3. Get Load Errors, see below.

This can also be reproduced by using Travis-CI's 2.7 environment on any of their images.

What did you expect to see
On Ruby 2.3 through 2.6 this results in the expected program execution.

What did you see instead?
On Ruby 2.7, on each platform I've tested on, this results in the following two errors:

[Snip]
1: from /home/travis/.rvm/gems/ruby-2.7.0/gems/google-protobuf-3.11.2-x86_64-linux/lib/google/protobuf.rb:49:in '<top (required)>'

/home/travis/.rvm/gems/ruby-2.7.0/gems/google-protobuf-3.11.2-x86_64-linux/lib/google/protobuf.rb:49:in require: cannot load such file -- google/2.7/protobuf_c (LoadError)

[Snip]

2: from /home/travis/.rvm/gems/ruby-2.7.0/gems/google-protobuf-3.11.2-x86_64-linux/lib/google/protobuf.rb:48:in <top (required)>

1: from /home/travis/.rvm/gems/ruby-2.7.0/gems/google-protobuf-3.11.2-x86_64-linux/lib/google/protobuf.rb:51:in rescue in <top (required)>

/home/travis/.rvm/gems/ruby-2.7.0/gems/google-protobuf-3.11.2-x86_64-linux/lib/google/protobuf.rb:51:in require: cannot load such file -- google/protobuf_c

Anything else we should know about your project / environment
This appears to be related to Ruby 2.7 releasing a few days after 3.11.2 released as it occurs on each system I try with 2.7 on it (including Travis-ci), but any older Ruby version works fine with 3.11.2. As 27 is a major release for Ruby and new installs will start to incorporate it, suggest either not letting the gem install on it, or putting out a bug fix to support 2.7 prior to the next release.

[ewalk153]

I have a draft PR in the works here: #7091

On MacOS, I'm getting a segfault before I can complete the test suite.

I had to run: ./tests.sh ruby27 after this to tests.sh:

build_ruby27() {
  internal_build_cpp  # For conformance tests.
  cd ruby && bash travis-test.sh ruby-2.7.0 && cd ..
}

[gerrywastaken]

Just leaving this so anybody else ending up at the, sadly locked, grpc thread will find their way here:
grpc/grpc#17744

And some searchable stuff:
Ruby 2.7 cannot load such file -- google/protobuf_c grpc bundle exec ./greeter_server.rb protobuf.rb

[rainchen]

same here, grpc fixed this: grpc/grpc#21514

[sriedel]

The load error is still present with ruby 2.7.0, grpc 1.28.0 and google protobuf 3.11.4

[kryptonat]

Any update on this? We're hoping to upgrade to ruby 2.7 and this is the only gem that is not compatible

[ewalk153]

I realize my PR #7091 was lingering in Draft mode. I've now marked it ready for review. Hopefully this helps moving things along.

[sophieyfang]

#7027 this is now merged

[ojundt]

Thanks for working on this issue. Unfortunately #7027 didn't fix it for me. I now get:

cannot load such file -- google/protobuf/any_pb

Trace:

/ruby/lib/google/protobuf/well_known_types.rb:32:in `<main>'

in Ruby 2.7.1 and 2.6.5.

[iagopiimenta]

Same error here

[douglara]

Here the same problem :/

[haberman]

To clarify, is this error coming from the gem or from GitHub master?

I believe we have merged all Ruby 2.7-related pull requests, so all we should need is a release to push them to Ruby Gems.

If that is not true, please speak up so we can figure out what we need to fix before the next release!

[micke]

What i've gathered is that the problem exists only in the precompiled lib.
Forcing a compilation fixes the issue.