Motivation

Fix building derivations in local chroot store on OpenAFS, where hard linking accross directories causes cross-device link error (EXDEV).

If applied, this patch enables HPC users to build packages with the statically-linked Nix binary where OpenAFS are used as the shared network-based FS.

We workaround similar situation for BeegFS this way in 05cc5a8.

It would be more ideal to bind-mount those paths when hard-linking is unsupported, but let's fix it first before having a more elegant solution.

Context

Fixes #8611

Cc: @Ericson2314

Checklist for maintainers

Maintainers: tick if completed or explain if not relevant

• agreed on idea
• agreed on implementation strategy
• tests, as appropriate
  • functional tests - tests/**.sh
  • unit tests - src/*/tests
  • integration tests - tests/nixos/*
• documentation in the manual
• documentation in the internal API docs
• code and comments are self-explanatory
• commit message explains why the change was made
• new feature or incompatible change: updated release notes

Priorities

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