You an enable the chromedriver log to debug and fix chromedriver and Selenium errors such as "unknown error: net::ERR_CONNECTION_REFUSED".
First start the chromedriver in the background:
```bash
nohup chromedriver --port=12345 --verbose --log-path=/tmp/chromedriver.log &
```
Then configure Selenium to use the chromedriver instance:
```bash
Capybara::Selenium::Driver.new(@app, browser: :chrome, options: ..., url: 'http://localhost:12345')
```
Next run the tests and inspect the chromedriver log.
In my case the issue was that an unreachable URL, see the unreachableUrl property in the output below:
```bash
[1659101781.048][DEBUG]: DevTools WebSocket Event: Page.frameNavigated B30A4B9FE0908FDACE0522341267520A {
"frame": {
"adFrameStatus": {
"adFrameType": "none"
},
"crossOriginIsolatedContextType": "NotIsolated",
"domainAndRegistry": "",
"gatedAPIFeatures": [ ],
"id": "B30A4B9FE0908FDACE0522341267520A",
"loaderId": "595BC7FEFD2C1ECCE31157FF7972F889",
"mimeType": "text/html",
"secureContextType": "InsecureScheme",
"securityOrigin": "://",
"unreachableUrl": "http://localhost:3030/",
"url": "chrome-error://chromewebdata/"
},
"type": "Navigation"
}
```
Thanks: https://makandracards.com/makandra/301588-how-to-enable-chromedriver-logging