rust-cpython: fix build for MacOSX
MacOSX needs special link flags. Quoting the README of rust-cpython:
create a `.cargo/config` with the following content:
```
[target.x86_64-apple-darwin]
rustflags = [
"-C", "link-arg=-undefined",
"-C", "link-arg=dynamic_lookup",
]
```
This is tested with Python 2.7 (Anaconda install) and Python 3
(Homebrew install)
--- a/setup.py Fri Jun 14 10:57:07 2019 +0100
+++ b/setup.py Fri Jun 14 11:18:06 2019 +0100
@@ -1199,6 +1199,9 @@
if sys.version_info[0] == 3 and self.py3_features is not None:
cargocmd.extend(('--features', self.py3_features,
'--no-default-features'))
+ if sys.platform == 'darwin':
+ env['RUSTFLAGS'] = ("-C link-arg=-undefined "
+ "-C link-arg=dynamic_lookup")
try:
subprocess.check_call(cargocmd, env=env, cwd=self.rustsrcdir)
except OSError as exc: