unpackPhase: fail when tar extract would overwrite files

[sedlund]

Description of changes

In unpackPhase when extracting with tar pass --keep-old-files which will cause tar to fail when it would normally silently overwrite files of the same name but with differing case on case insensitive filesystems (darwin).

This prevents errors when building packages such as #341455 . Which causes packages to have differing hashes.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 24.11 Release Notes (or backporting 23.11 and 24.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[sedlund]

@ajs124 @fpletz

this change breaks tzdata as it unpacks two tarballs with the same filenames over eachother.

Do you have input on how to rectify?

tzdata build

tzdata> Running phase: unpackPhase
tzdata> unpacking source archive /nix/store/39z4s69v0rs5q41x1bpwy8qpark4bd7i-tzdata2024a.tar.gz
tzdata> unpacking source archive /nix/store/yl79i12bnsg5qb38v4fbmpg8mk3k2yd3-tzcode2024a.tar.gz
tzdata> tar: calendars: Cannot open: File exists
tzdata> tar: CONTRIBUTING: Cannot open: File exists
tzdata> tar: LICENSE: Cannot open: File exists
tzdata> tar: Makefile: Cannot open: File exists
tzdata> tar: NEWS: Cannot open: File exists
tzdata> tar: README: Cannot open: File exists
tzdata> tar: SECURITY: Cannot open: File exists
tzdata> tar: theory.html: Cannot open: File exists
tzdata> tar: version: Cannot open: File exists
tzdata> tar: Exiting with failure status due to previous errors
tzdata> do not know how to unpack source archive /nix/store/yl79i12bnsg5qb38v4fbmpg8mk3k2yd3-tzcode2024a.tar.gz
error: builder for '/nix/store/f9dllqivwbnz79fxxh9wrqjbzs2yjzmk-tzdata-2024a.drv' failed with exit code 1;
       last 14 log lines:
       > Running phase: unpackPhase
       > unpacking source archive /nix/store/39z4s69v0rs5q41x1bpwy8qpark4bd7i-tzdata2024a.tar.gz
       > unpacking source archive /nix/store/yl79i12bnsg5qb38v4fbmpg8mk3k2yd3-tzcode2024a.tar.gz
       > tar: calendars: Cannot open: File exists
       > tar: CONTRIBUTING: Cannot open: File exists
       > tar: LICENSE: Cannot open: File exists
       > tar: Makefile: Cannot open: File exists
       > tar: NEWS: Cannot open: File exists
       > tar: README: Cannot open: File exists
       > tar: SECURITY: Cannot open: File exists
       > tar: theory.html: Cannot open: File exists
       > tar: version: Cannot open: File exists
       > tar: Exiting with failure status due to previous errors
       > do not know how to unpack source archive /nix/store/yl79i12bnsg5qb38v4fbmpg8mk3k2yd3-tzcode2024a.tar.gz
       For full logs, run 'nix log /nix/store/f9dllqivwbnz79fxxh9wrqjbzs2yjzmk-tzdata-2024a.drv'.

[alyssais]

Please include explanation for your changes in the commit messages, not just the PR body.