update-bash issues

[bfontaine]

As @xu-cheng reported it prints a bunch of error messages if you ^C it:

$ brew update-bash
^Cfatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

fatal: Could not read from remote repository.
...snip...

---

You also get a bunch of error messages (one per tap I guess) if you’re not connected to the Internet:

$ brew update-bash
ssh: Could not resolve hostname github.com: nodename nor servname provided, or not known
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
...snip...
fatal: unable to access 'https://github.com/caskroom/homebrew-cask/': Could not resolve host: github.com
ssh: Could not resolve hostname github.com: nodename nor servname provided, or not known
fatal: Could not read from remote repository.
...snip...

[MikeMcQuaid]

@bfontaine @xu-cheng I'm not sure how best to address either of these; thoughts?

[bfontaine]

I’m not sure either right now 😕

[DomT4]

You also get a bunch of error messages (one per tap I guess) if you’re not connected to the Internet:

Could possibly do something super simple like:

ping -c 2 8.8.8.8 &> /dev/null || echo "Update cannot be run offline!"; exit 1

The chance of 8.8.8.8 ever being down is about as close to zero as you can get.

Edit - You couldn't stick an exit 1 there thinking about it, because it always would I believe. You could expand it though to deal with that, such as:

if ! ping -c 2 8.8.8.8 &> /dev/null
then
  echo "Update cannot be run offline!"
  exit 1
fi

Edit to the edit - ping might be the wrong thing to use, it seems to hang if there's no route to the host rather than exiting cleanly. We could use curl though via something like:

curl -I --connect-timeout 2 https://www.debian.org &> /dev/null

[bfontaine]

@DomT4 Good idea; we might want to ping/curl github.com instead since that what we’ll use to update. We might also want to use a message more generic like “Cannot connect to {github.com,Internet}”.

[DomT4]

@bfontaine I was thinking about that but Github is consistently twice as slow to respond to a header request as Debian is. We're talking 0.3 and 0.6 seconds where the connection is available, so not huge numbers, so we may not care.

[DomT4]

Filed a PR for review. Easier to discuss real ideas which can be pulled/tested than theoretical ideas, etc.