Reproduction scenario for googleapis/google-cloud-go#11089

1. Install squid
2. Enable the access log configuration for squid by running:

echo "\naccess_log $(pwd)/squid_access.log squid" >> squid/squid.conf

3. Run squid -f squid/squid.conf to start the proxy
4. Run the following command from the root of the repository, see that it ends without errors

cd old && GOOGLE_CLOUD_PROJECT=<replace-with-project> https_proxy=http://localhost:3128 go run main.go

5. Run the following command from the root of the repository, see that it hangs since the proxy blocks IPs, but allows domains (you can see the access logs in squid_access.log)

cd new && GOOGLE_CLOUD_PROJECT=<replace-with-project> https_proxy=http://localhost:3128  go run main.go

The differences are that the old directory uses the cloud.google.com/go/[email protected] that references cloud.google.com/go/[email protected], and the new directory uses the cloud.google.com/go/[email protected] that references cloud.google.com/go/[email protected].

Setting export GOOGLE_API_GO_EXPERIMENTAL_DISABLE_NEW_AUTH_LIB=true will make the new directory work as expected.