Rollup merge of #90800 - aplanas:fix_cargo_config, r=Mark-Simulacrum

bootstap: create .cargo/config only if not present

In some situations we should want on influence into the .cargo/config
when we use vendored source.  One example is #90764, when we want to
workaround some references to crates forked and living in git, that are
missing in the vendor/ directory.

This commit will create the .cargo/config file only when the .cargo/
directory needs to be created.

src/bootstrap/bootstrap.py

@@ -1119,17 +1119,22 @@ def check_vendored_status(self):
  raise Exception("{} not found".format(vendor_dir))
 
  if self.use_vendored_sources:
+ config = ("[source.crates-io]\n"
+ "replace-with = 'vendored-sources'\n"
+ "registry = 'https://example.com'\n"
+ "\n"
+ "[source.vendored-sources]\n"
+ "directory = '{}/vendor'\n"
+ .format(self.rust_root))
  if not os.path.exists('.cargo'):
  os.makedirs('.cargo')
- with output('.cargo/config') as cargo_config:
- cargo_config.write(
- "[source.crates-io]\n"
- "replace-with = 'vendored-sources'\n"
- "registry = 'https://example.com'\n"
- "\n"
- "[source.vendored-sources]\n"
- "directory = '{}/vendor'\n"
- .format(self.rust_root))
+ with output('.cargo/config') as cargo_config:
+ cargo_config.write(config)
+ else:
+ print('info: using vendored source, but .cargo/config is already present.')
+ print(' Reusing the current configuration file. But you may want to '
+ 'configure vendoring like this:')
+ print(config)
  else:
  if os.path.exists('.cargo'):
  shutil.rmtree('.cargo')