The recently merged #34143 broke builds with depends on NetBSD due to a workaround introduced in 5a5ddbd78922236402df378c8588a7b0b3f83a13.
The upstream bug has been fixed, and the entire workaround can be removed once the fixed Boost package becomes generally available.
However, it seems prudent to amend the workaround now to have it workable in the 31.0 release.
Here are CI runs: