fix: elan: use relative paths in wrapper script

[nomeata]

since 3.1.1, elan extracts to a temporary location and then moves to a final location, this threw the wrapper script off. Updating the patch to use paths relative to the wrapper script, so that it works independent of absolute location.

Tested like this:

~/build/lean/mathlib4 $ nix run ~/build/nixpkgs#elan -- run --install $(cat lean-toolchain) lake exec cache
warning: Git tree '/home/jojo/build/nixpkgs' is dirty
info: std: cloning https://github.com/leanprover/std4 to './.lake/packages/std'
info: Qq: cloning https://github.com/leanprover-community/quote4 to './.lake/packages/Qq'
info: aesop: cloning https://github.com/leanprover-community/aesop to './.lake/packages/aesop'
info: proofwidgets: cloning https://github.com/leanprover-community/ProofWidgets4 to './.lake/packages/proofwidgets'
info: Cli: cloning https://github.com/leanprover/lean4-cli to './.lake/packages/Cli'
info: importGraph: cloning https://github.com/leanprover-community/import-graph.git to './.lake/packages/importGraph'
info: [0/9] Downloading proofwidgets cloud release
info: [0/9] Unpacking proofwidgets cloud release
info: [1/9] Building Cache.IO
info: [2/9] Compiling Cache.IO
info: [2/9] Building Cache.Hashing
info: [3/9] Compiling Cache.Hashing
info: [3/9] Building Cache.Requests
info: [4/9] Compiling Cache.Requests
info: [4/9] Building Cache.Main
info: [6/9] Compiling Cache.Main
info: [9/9] Linking cache
Mathlib4 caching CLI
Usage: cache [COMMAND]

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/)
• 24.05 Release Notes (or backporting 23.05 and 23.11 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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[collares]

Can you remove the patch reverting the temporary directory creation (that is, revert #294040)? Thanks!

[nomeata]

Ah, I didn’t even see that there was another fix applied. Revert added to this branch!

[collares]

The commit convention would be to start the commit message with elan: instead of fix: , but I don't think this warrants another round of changes. Thank you for fixing this!

[nomeata]

Sorry, I sometimes get confused when contributing to different projects :-). Thanks for merging!