Version sub-command hangs on latest watchman release - macOS

The `watchman version` command hangs after I upgraded to a newer watchman release v20200726.234435.0. I am running macOS 10.15.6.

## Steps to repro
```
$ watchman version

$ watchman --version
20200726.234435.0
```

## Notes
It seems that "watchman version" hangs on watchman v20200726.234435.0 and that the new way to check the version is to use "watchman --version" instead. Not sure if the watchman backwards compat applies to the cli, but maybe this is an unintended breaking change.

I tracked down the issue to watchman because this broke the relay-compiler cli for me. This line here shows that "watchman version" is being used by relay-compiler to check if watchman is installed:
https://github.com/facebook/relay/blob/191ca8b0f24759665006ac442f4aeaa3bd9482fd/packages/relay-compiler/core/GraphQLWatchmanClient.js#L29

I am able to workaround the issue by running compiler with "--no-watchman" or downgrading to v4, but would be nice to keep the old command working and avoid changes.

Edit: There are also no logs and `watchman watch-del-all` and other commands also hang.