macvim: 7.4.909 -> 8.1.1517

[lilyball]

Motivation for this change

Fix up the macvim package to build again, with the latest snapshot. The patchfile has been recreated by manually reapplying all of the changes from the old patchfile, and the other changes in here were figured out by trial and error (such as the need to unset LD).

Also tweak the package to use python37 by default, and add an option to go back to python27 if desired. I'm not actually sure what the most common python configuration is these days, so this was chosen mostly because python3 is supposed to be the future.

Disable Sparkle so the user isn't prompted to update a readonly package.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

---

This build is impure. It relies on accessing a few tools from /usr/bin (including xcodebuild), and it sets the minimum deployment target to the current OS version. I tried patching the latter but that resulted in a bunch of warnings during the build process, so I left it alone. This impurity exists for the current broken package too, of course.

CC @cstrahan

[lilyball]

I tested some basic functionality, such as :py3 print("hello") and :ruby print("hello"). I also verified that it builds with usePython27 set (and that :py print("hello") works there). I was somewhat tempted to just enable both python2 and python3 simultaneously, which apparently works with some limitations, but decided it was better not to.

[lilyball]

Updated to the just-released snapshot-156 which includes a fix for the recent Vim CVE (relating to modelines).

[lilyball]

I've also gone ahead and added myself as a maintainer.

[nixos-discourse]

This pull request has been mentioned on Nix community. There might be relevant details there:

https://discourse.nixos.org/t/prs-ready-for-review-may-2019/3032/19

[matthewbauer]

This could cause issues when /usr/bin/ibtool doesn't exist. Probably we should follow the Hydra builds to see. I think a darwin.ibtool might be useful to give a nice error message when this doesn't exist.

[lilyball]

What version of macOS does Hydra run on, and what's the minimum version of macOS that Nix supports? /usr/bin/ibtool should exist on any version of macOS from the past few years at least. I suppose this could be /usr/bin/xcrun ibtool instead if we need to support a version of macOS that predates the introduction of the full set of build tools into /usr/bin.