Bundler 2.2.5 still doesn't fallback to source gem when platform specific gem is unusable

[casperisfine]

Ref: rubygems/bundler#7522

From what I understood, bundler 2.2.x was supposed to fallback to compiling gems if the precompiled binaries can't be used.

But from what I experienced it still doesn't work:

Using bundler 2.2.5

google-protobuf-3.14.0-x86_64-linux requires ruby version < 2.8.dev, >= 2.3,
which is incompatible with the current version, ruby 3.0.0p0

[deivid-rodriguez]

Yes, definitely. This should work.

I suspect bundler resolution is sometimes falling back to the old gem dependency API which didn't have required_ruby_version information so even if the resolver is now correct, it's lacking some information.

I don't know why this is happening, but we have received two reports about this in the last 2 days, hence my suspicion. It could be a server side issue too, I'll investigate. Can you post some logs that I can see, ideally in verbose mode so we can see the network requests being made.

I suspect this is not reproducible reliably, correct?

[casperisfine]

Can you post some logs that I can see, ideally in verbose mode so we can see the network requests being made.

Our gemfile is huge and contains lots of private gems. I'll try to better reproduce in isolation and provide logs.

I suspect this is not reproducible reliably, correct?

Yes. I'm trying to pinpoint it exactly, but it isn't quite trivial. I'll try to come back with a repro script.

[casperisfine]

Ok, I think I figured it out:

source 'https://rubygems.org'

gem 'grpc'

Ruby 2.7.2: bundle install, generates the following Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    google-protobuf (3.14.0-universal-darwin)
    googleapis-common-protos-types (1.0.5)
      google-protobuf (~> 3.11)
    grpc (1.34.0-universal-darwin)
      google-protobuf (~> 3.13)
      googleapis-common-protos-types (~> 1.0)

PLATFORMS
  x86_64-darwin-19

DEPENDENCIES
  grpc

BUNDLED WITH
   2.2.5

Then chruby 3.0.0:

$ bundle install
$ bundle
Fetching gem metadata from https://rubygems.org/.........
google-protobuf-3.14.0-universal-darwin requires ruby version < 2.8.dev, >= 2.3, which is incompatible with the current version, ruby 3.0.0p0

$ diff Gemfile.lock Gemfile.lock.2.7 
4c4
<     google-protobuf (3.14.0)
---
>     google-protobuf (3.14.0-universal-darwin)
7c7
<     grpc (1.34.0)
---
>     grpc (1.34.0-universal-darwin)

So the problem seem to be that our Gemfile.lock was generated with Ruby 2.7, so it recorded the precompiled gem as usable. Then when we switch to 3.0 (because we aren't fully migrated yet) it tries to use the same version.

I'll see if I can find a workaround for us, but this seems like a bug to me. It's not uncommon to use the same Gemfile.lock concurrently with different ruby versions.

[deivid-rodriguez]

Oh, I see... But, how can we solve that?

In this case two different ruby versions have two different resolutions. I think if you want to reuse the same lockfile for both rubies you could use #4049, making the compromise of giving up on platform specific variants for this gem.

I'm open to suggestions.

[casperisfine]

There might be more to it though, because in our app I don't see the compiled gem being listed in Gemfile.lock:

$ bundle --version
Bundler version 2.2.5
$ bundle
Resolving dependencies....................
Fetching source index from https://rubygems.org/
google-protobuf-3.14.0-universal-darwin requires ruby version >= 2.3, < 2.8.dev, which is incompatible with the current version, ruby 3.0.0p0
$ grep google-protobuf Gemfile.lock 
      google-protobuf
      google-protobuf
    google-protobuf (3.14.0)
      google-protobuf (~> 3.11)
      google-protobuf (~> 3.13)
      google-protobuf (>= 3.4.1.1, < 4)
  google-protobuf

how can we solve that?

I'm afraid I'm not familiar enough with bundler internal to offer much help on this.

Couldn't bundler always list the source gem even when it select the platform specific one? Or list all variants?

I haven't dug much yet, but that Gemfile.lock I posted above looks fishy to me. It list OSX specific stuff, but then we run our CI on linux. I've also seem dependabot PRs (generated on linux) include linux specific gem name but no osx or source ones.

[casperisfine]

you could use #4049, making the compromise of giving up on platform specific variants for this gem.

I've wished for this feature for a while. It wouldn't be perfect, but at least it would unblock me I think.

[deivid-rodriguez]

Can you try bundle lock --add-platform ruby. That should also keep generic variants in the lockfile and I think should fix things.

[casperisfine]

That should also keep generic variants in the lockfile

It did:

diff --git a/Gemfile.lock b/Gemfile.lock
index 38d4965..5240cee 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,13 +2,18 @@ GEM
   remote: https://rubygems.org/
   specs:
     google-protobuf (3.14.0)
+    google-protobuf (3.14.0-universal-darwin)
     googleapis-common-protos-types (1.0.5)
       google-protobuf (~> 3.11)
     grpc (1.34.0)
       google-protobuf (~> 3.13)
       googleapis-common-protos-types (~> 1.0)
+    grpc (1.34.0-universal-darwin)
+      google-protobuf (~> 3.13)
+      googleapis-common-protos-types (~> 1.0)
 
 PLATFORMS
+  ruby
   x86_64-darwin-19

I think should fix things.

I'm afraid not:

$ bundle install
Fetching gem metadata from https://rubygems.org/.........
google-protobuf-3.14.0-universal-darwin requires ruby version < 2.8.dev, >= 2.3, which is incompatible with the current version, ruby 3.0.0p0

[casperisfine]

More logs:

$ bundle install --verbose
Running `bundle install --verbose` with bundler 2.2.5
Found no changes, using resolution from the lockfile
The definition is missing ["google-protobuf-3.14.0-universal-darwin", "grpc-1.34.0-universal-darwin"]
HTTP GET https://index.rubygems.org/versions
HTTP 206 Partial Content https://index.rubygems.org/versions
Fetching gem metadata from https://rubygems.org/
Looking up gems ["google-protobuf", "googleapis-common-protos-types", "grpc"]
Looking up gems ["faraday", "googleauth", "jwt", "logging", "minitest", "multi_json", "signet", "xray"]
Looking up gems ["flexmock", "lockfile", "rake", "little-plugger", "addressable", "rack", "multipart-post", "ruby2_keywords", "faraday-net_http", "memoist", "os", "json", "httpadapter", "extlib"]
Looking up gems ["rspec", "public_suffix", "english", "hoe"]
Looking up gems ["rubyforge", "RubyInline", "gemcutter", "rspec-core", "rspec-expectations", "rspec-mocks"]
Looking up gems ["ZenTest", "rspec-support", "diff-lcs", "json_pure", "net-scp"]
Looking up gems ["spruz", "net-ssh"]
Looking up gems ["needle", "jruby-pageant", "bcrypt_pbkdf", "rbnacl", "rbnacl-libsodium"]
Looking up gems ["ffi"]
google-protobuf-3.14.0-universal-darwin requires ruby version < 2.8.dev, >= 2.3, which is incompatible with the current version, ruby 3.0.0p0
Bundler::InstallError: google-protobuf-3.14.0-universal-darwin requires ruby version < 2.8.dev, >= 2.3, which is incompatible with the current version, ruby 3.0.0p0

[deivid-rodriguez]

That's unexpected, I would expect bundle lock --add-platform ruby to add only generic variants to the lockfile. That's a bug I'd say, I'll look into it.

Sorry for the issues you're having, a correct multiplatform resolution turned out to be much harder than I was expecting 🙏.

[casperisfine]

No worries, I mostly blame grpc and google-protobuf to be honest :p, they're a huge pain to work with.

And lots of thanks for trying to make this work, I'll try to figure a workaround in the meantime. I used to have a shitty monkey patch to force these gems be source gems, but it no longer works on 2.2.x, I'll have to figure out something:

if RUBY_VERSION >= '3.0'
  module BundlerHack
    def __materialize__
      if name == 'google-protobuf'
        Bundler.settings.temporary(force_ruby_platform: true) do
          super
        end
      else
        super
      end
    end
  end
  Bundler::LazySpecification.prepend(BundlerHack)
end

[casperisfine]

So I don't quite understand how or why, but but looking at the diffs better I saw that 2.7 had PLATFORMS ruby and if I were to re-bundle from scratch 3.0 would have PLATFORMS x86_64-darwin-19.

So I manually edited the Gemfile.lock such as:

diff --git a/Gemfile.lock b/Gemfile.lock
index 377e56dfba68..8bbea0be4a27 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2700,6 +2700,7 @@ GEM
 
 PLATFORMS
   ruby
+  x86_64-darwin-19
 

And it now install properly on 3.0. That's really puzzling to me though.

[rromanchuk]

@casperisfine i just manually added + x86_64-darwin-19 to my lockfile and it finally worked. I didn't even get as far as figuring out it was from grpc. Luckily your google-protobuf got indexed and you just saved me many hours. Any luck on figuring out the "why" yet?

[casperisfine]

You mean why bundler doesn't fallback to source? No not yet.