Rubygems: error fetching rubygems data, falling back to versions-only result

[rarkins]

Discussed in #36623

^{Originally posted by EugeneBad June 20, 2025}

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When pulling dependencies from rubygems.org eg with this Gemsfile:

source 'https://rubygems.org'

ruby '3.4.2'

gem '[bootsnap](https://rubygems.org/gems/bootsnap)', '~> 1.18'
gem '[rails](https://rubygems.org/gems/rails)', '~> 8.0'

The error "Rubygems: error fetching rubygems data, falling back to versions-only result" will get triggered because Renovate's internal consistency check (dataHash === versionsHash) fails. Here

The Root Cause: When creating the metadata-cache, renovate's rubygems datasource will fetch version lists from two places: 1. from https://rubygems.org/versions endpoint
2. from https://rubygems.org/api/v1/versions/<package_name>.json endpoint.
This is documented in the datasource's readme.
It then compares the hashes of the version strings returned by both endpoints ie a versionsHash and dataHash respectively.

For some reason, the version strings returned by the former will sometimes include platform suffixes like -java in the version string, e.g., "1.1.0-java" which differs from the version list extracted from the latter (which only provides the base version number, e.g., "1.1.0"). These differing string representations lead to different hashes, hence the error.

A package like bootsnap for example:

• https://rubygems.org/versions endpoint :

bootsnap 0.2.0,0.2.1,0.2.2,0.2.3,0.2.4,0.2.5,0.2.6,0.2.7,0.2.8,0.2.9,0.2.10,0.2.11,0.2.12,0.2.13,0.2.14,0.2.15,0.3.0.pre,0.3.0.pre2,0.3.0.pre3,0.3.0,0.3.1,0.3.2,1.0.0,1.1.0.pre,1.1.0.pre-java,1.1.0,1.1.0-java,1.1.1,1.1.1-java,1.1.2,1.1.2-java,1.1.3,1.1.3-java,1.1.4-java,1.1.5,1.1.5-java,1.1.6.beta,1.1.6.beta2,1.1.6.beta3,1.1.6,1.1.6-java,1.1.7,1.1.7-java,1.1.8-java,1.1.8,1.2.0.pre,1.2.0.pre-java,1.2.0,1.2.0-java,1.2.1,1.2.1-java,1.3.0.beta,1.3.0.beta-java,1.3.0.beta2,1.3.0.beta2-java,1.3.0,1.3.0-java,1.3.1,1.3.1-java,1.3.2,1.3.2-java,1.4.0.pre2,1.4.0.pre3,1.4.0-java,1.4.0,1.4.1,1.4.1-java,1.4.2.rc1,1.4.2.rc1-java,1.4.2.rc2,1.4.2.rc2-java,1.4.2.rc3,1.4.2,1.4.2-java,1.4.3,1.4.3-java,1.4.4,1.4.4-java,1.4.5,1.4.5-java,1.4.6,1.4.6-java,1.4.7-java,1.4.7,1.4.8,1.4.8-java,1.4.9.rc1,1.4.9,1.4.9-java,1.5.0,1.5.1,1.5.0-java,1.5.1-java,1.6.0,1.7.0,1.7.1.pre1,1.7.1,1.7.2,1.7.3,1.7.4,1.7.5,1.7.6,1.7.7,1.8.0,1.8.1,1.9.0,1.9.1,1.9.2,1.9.3,1.9.4,1.10.0,1.10.1,1.10.2,1.10.3,1.11.0,1.11.1,1.12.0,1.13.0,1.14.0,1.15.0,1.16.0,1.17.0,1.17.1,1.18.0,1.18.1,1.18.2,1.18.3,1.18.4,1.18.5,1.18.6

• https://rubygems.org/api/v1/versions/bootsnap.json endpoint
  Will not have platform suffixed version numbers

["1.18.6","1.18.5","1.18.4","1.18.3","1.18.2","1.18.1","1.18.0","1.17.1","1.17.0","1.16.0","1.15.0","1.14.0","1.13.0","1.12.0","1.11.1","1.11.0","1.10.3","1.10.2","1.10.1","1.10.0","1.9.4","1.9.3","1.9.2","1.9.1","1.9.0","1.8.1","1.8.0","1.7.7","1.7.6","1.7.5","1.7.4","1.7.3","1.7.2","1.7.1","1.7.1.pre1","1.7.0","1.6.0","1.5.1","1.5.1","1.5.0","1.5.0","1.4.9","1.4.9","1.4.9.rc1","1.4.8","1.4.8","1.4.7","1.4.7","1.4.6","1.4.6","1.4.5","1.4.5","1.4.4","1.4.4","1.4.3","1.4.3","1.4.2","1.4.2","1.4.2.rc3","1.4.2.rc2","1.4.2.rc2","1.4.2.rc1","1.4.2.rc1","1.4.1","1.4.1","1.4.0","1.4.0","1.4.0.pre3","1.4.0.pre2","1.3.2","1.3.2","1.3.1","1.3.1","1.3.0","1.3.0","1.3.0.beta2","1.3.0.beta2","1.3.0.beta","1.3.0.beta","1.2.1","1.2.1","1.2.0","1.2.0","1.2.0.pre","1.2.0.pre","1.1.8","1.1.8","1.1.7","1.1.7","1.1.6","1.1.6","1.1.6.beta3","1.1.6.beta2","1.1.6.beta","1.1.5","1.1.5","1.1.4","1.1.3","1.1.3","1.1.2","1.1.2","1.1.1","1.1.1","1.1.0","1.1.0","1.1.0.pre","1.1.0.pre","1.0.0","0.3.2","0.3.1","0.3.0","0.3.0.pre3","0.3.0.pre2","0.3.0.pre","0.2.15","0.2.14","0.2.13","0.2.12","0.2.11","0.2.10","0.2.9","0.2.8","0.2.7","0.2.6","0.2.5","0.2.4","0.2.3","0.2.2","0.2.1","0.2.0"]

Note that this error doesn't prevent renovate from updating the dependency.

The Solution:

1. Change this log type from error to just an info, since renovate already gracefully handles the discrepancy between version lists by falling back to a "versions-only result.
2. Rework the parsing logic in versions-endpoint-cache.ts file; to strip these platform suffixes, ensuring that both lists of versions are normalized before being hashed.

Logs (if relevant)

Logs

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