MacVim compiles the Vim part using `/usr/bin/clang` and the GUI part
using Xcode. The Xcode portion always uses Xcode's own SDK and we have
no workable alternative. The Vim portion so far has been compiling using
a hybrid compilation environment, where it uses the SDK for most stuff
but picks up a bunch of library linker paths (including libSystem) by
virtue of Ruby's LDFLAGS. This hybrid compilation environment meant that
if the SDK headers referenced a symbol that the library itself didn't
have, this could produce link errors.
Previously we attempted to fix this by synthesizing an include path that
contained just the one header from Nix's Libsystem that referenced the
missing symbol, to get rid of the reference and allow linking to work
again, but this was very hacky and runs the risk of future Xcode SDK
changes producing the same errors with different headers, or of future
SDK versions expecting the intercepted header to contain a definition
that Nix's doesn't.
This new approach is to just clean up the compilation environment such
that the Vim portion is compiling against the Xcode SDK as well, by
sanitizing the LDFLAGS produced by the configure script so it stops
referencing Nix's versions of OS libraries. This means the resulting Vim
binary no longer depends at runtime on Nix for anything except the
scripting language support, but that's how it's been for the MacVim
binary all along anyway, and this approach should keep us insulated
against future Xcode SDK changes.
This fixes several Xcode 11 incompatibilities with MacVim, including an
issue where it wasn't inheriting the deployment target correctly to
begin with.
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.
Disable Sparkle so the user isn't prompted to update a readonly package.
MacVim's maintenance has stagnated, so this moves `macvim` to a new maintainer.
Additionally, the `-headerpad_max_install_names` linker flag is passed to
prevent problems when setting the rpaths.
