There is an updated pull request by sgn against master on the void-packages repository

https://github.com/sgn/void-packages unset-exported-var
https://github.com/void-linux/void-packages/pull/40359

env/setup/sourcepkg: unset all exported variables
except known to be good one.

See 581cdacc5b and 253b9f0b98

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A patch file from https://github.com/void-linux/void-packages/pull/40359.patch is attached