Summary:
Our environment-stripping logic used in `config/env.js` to read the
current Git state included stripping the `PATH` environment variable.
This had the effect that the system Git executable would always be used
in preference to a user-installed version.
Test Plan:
Run `/usr/bin/git --version`, and then install a different version of
Git. (For instance, check out an old tag, then `make && make install`
from the `git/git` repository.) Then, add
```js
console.log(execFileSync("git", ["--version"], {env}).toString());
```
to `getGitState` in `config/env.js`, and run
NODE_ENV=development node ./config/env.js
Note that this prints the version of the system Git before this change,
and the user Git after this change.
Alternately, local-install a version of Git earlier than 2.6.0, and note
that `yarn unit` now _fails_ because the `--date=format:…` syntax is not
known to such versions of Git. Prior to this commit, the tests would
pass as long as the system Git were more recent.
wchargin-branch: env-git-path
440b6c2567