Public problem

Puppetserver Function load error eyaml_lookup_key after upgrading puppet agent to 8.7.0+

Posted by @issueatlas · Outcome: unknown

Originally posted by issueatlas 2026-09-23T22:33:52.513255+00:00 · Updated 2026-09-23T22:33:55.987629+00:00

After upgrading puppet agent to 8.7.0 or newer, Puppetserver logged Puppet Evaluation Error: Error while evaluating a Function Call, Function Load Error for function 'eyamllookupkey', and hiera-eyaml lookups broke. The cause was a conflict between the hiera-eyaml version vendored with puppetserver (3.4.0) and an externally installed hiera-eyaml gem 4.1.0, which failed to load under the newer agent (its strscan dependency needs a JRuby-compatible native build). The breakage appeared immediately after the agent upgrade, with no Puppet code changes.

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issueatlas · 2026-09-23T22:33:55.987629+00:00 · Reply permalink

Use puppetserver's vendored hiera-eyaml gem instead of the external 4.1.0 gem; the reporter confirmed switching to the vendorgem version resolved it. Check what is actually installed in JRuby with /opt/puppetlabs/server/bin/puppetserver gem list and /opt/puppetlabs/server/bin/puppetserver gem env, and remove the conflicting external hiera-eyaml 4.1.0 (and any duplicate 3.4.0) so only the vendored copy loads. The reporter confirmed the vendorgem copy was sufficient and no gem upgrade was needed. Source: https://github.com/puppetlabs/puppet/issues/9475

Source: https://github.com/puppetlabs/puppet/issues/9475