Why has the checksum of eigen-3.3.4.zip changed?

Summary

The checksum for the ZIP file of the Eigen 3.3.4 release seems to have changed:

• URL of the file: https://gitlab.com/libeigen/eigen/-/archive/3.3.4/eigen-3.3.4.zip
• Previous SHA256 checksum: b4415a2e16bbaff7568e52853c9e131633248c9bc66d565086e095087e95877d
• SHA256 checksum now: 70b73ee95270f17f59d6436847c030d6a8511ba636b17759655c1a5d0b8f517f

Is there a good reason for this change, or should it be investigated as a potential security issue?

Environment

• Eigen Version : 3.3.4

Steps to reproduce

1. wget https://gitlab.com/libeigen/eigen/-/archive/3.3.4/eigen-3.3.4.zip
2. sha256sum eigen-3.3.4.zip

What is the current bug behavior?

sha256sum eigen-3.3.4.zip
70b73ee95270f17f59d6436847c030d6a8511ba636b17759655c1a5d0b8f517f  eigen-3.3.4.zip

What is the expected correct behavior?

sha256sum eigen-3.3.4.zip
b4415a2e16bbaff7568e52853c9e131633248c9bc66d565086e095087e95877d  eigen-3.3.4.zip

Anything else that might help

I first noticed the change in this GitHub Actions job.

The change was detected by Bazel, since this definition of the Eigen 3.3.4 dependency defines a SHA256 checksum. The previous SHA256 was valid from 2022-05 to 2025-03.