Handle ERROR: While executing gem ... (Zlib::BufError)?

[dentarg]

I've seen this happening a couple of times:

Run gem install gem-compare --version 1.1.0
Successfully installed rainbow-3.1.1
Successfully installed gemnasium-parser-0.1.9
Successfully installed diffy-3.4.2
Successfully installed gem-compare-1.1.0
4 gems installed
Run gem compare $COMPARE_GEM $COMPARE_FROM_VERSION $COMPARE_TO_VERSION > compare_output.txt
NOTE: Gem::Specification#has_rdoc is deprecated with no replacement. It will be removed in Rubygems 4
Gem::Specification#has_rdoc called from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/gem-compare-1.1.0/lib/rubygems/comparator/utils.rb:112.
NOTE: Gem::Specification#has_rdoc is deprecated with no replacement. It will be removed in Rubygems 4
Gem::Specification#has_rdoc called from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/gem-compare-1.1.0/lib/rubygems/comparator/utils.rb:112.
Run gem compare --diff $COMPARE_GEM $COMPARE_FROM_VERSION $COMPARE_TO_VERSION > compare_diff.txt
ERROR:  While executing gem ... (Zlib::BufError)
    buffer error

This is probably not the fault of this plugin, rather a temporary transport/network issue. Maybe rubygems.org does some rate limiting. Nevertheless, it would be cool to handle it, if possible.

We can see that the first gem compare command worked, is the second one fetching the gems again from RubyGems.org?

GitHub Actions log at https://github.com/Starkast/wikimum/runs/7173057743?check_suite_focus=true#step:2:454

(I've made an action that runs this plugin on Dependabot PRs and makes comment with the comparison, https://github.com/dentarg/gem-compare)

[strzibny]

Do you have a suggestion on how to address this?

[dentarg]

Not yet :)

[dentarg]

For now I've worked around this issue with retries outside gem compare.

[dentarg]

Maybe ruby/zlib#61 will make a difference for this (just a guess)

[martinemde]

Could you try with the latest rubygems? We recently added something that will give a better report when a file reaches an eof unexpectedly. It might at least reveal if this is a problem with the downloaded file.

For what it's worth, gem-compare is simply calling Gem::Package#extract_files. It's not doing anything "fancy" so this is either internal to rubygems, or zlib (as you mentioned) or caused by network issues when downloading.

[strzibny]

Yes, it would be better to open an issue in RubyGems and/or Zlib, and just link the issue.

[dentarg]

Could you try with the latest rubygems?

I'm not running gem compare by hand, I'm using my action https://github.com/dentarg/gem-compare to run it on Dependabot PRs. It uses whatever RubyGems setup-ruby picks, https://github.com/ruby/setup-ruby#rubygems, which seems to be the RubyGems that comes with Ruby.

Here's a recent run using Ruby 3.1.4 where the problem still showed: https://github.com/Starkast/wikimum/actions/runs/6154045239/job/16698800533#step:2:85

Here's a recent run using Ruby 3.2.2 where the problem still showed:
https://github.com/dentarg/burd/actions/runs/5905770058/job/16020494333#step:2:95

Looks like Ruby 3.2.2 ships with RubyGems 3.4.10? Is that recent enough?

I guess I could always install the latest RubyGems at the cost of somewhat slower CI runs.