There is a new pull request by Calandracas606 against master on the void-packages repository

https://github.com/Calandracas606/void-packages eigen-3.4
https://github.com/void-linux/void-packages/pull/50215

eigen: update to 3.4.0, adopt.
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#### Testing the changes
- I tested the changes in this PR: **briefly**

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#### Local build testing
- I built this PR locally for my native architecture, x86_64-glibc
- I built this PR locally for these architectures (if supported. mark crossbuilds):
  - x86_64-musl
  - i686
  - aarch64 (cross)
  - aarch64-musl (cross)
  - armv7l (cross)
  - armv7l-musl (cross)
  - armv6l (cross)
  - armv6l-musl (cross)



A patch file from https://github.com/void-linux/void-packages/pull/50215.patch is attached