fix(dns): display a more informative message in case we can't resolve

Tested in Linux. When offline, /etc/resolve.conf is a broken symlink,
so opening it yields an IO error. It should work similarly in other OSs as the
resolver is OS-agnostic.

Before, the message was simply: Error: io error. After this change, a more
informative message is shown.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/os/shared.rs b/src/os/shared.rs
index 852d4f7..afa7330 100644
--- a/src/os/shared.rs
+++ b/src/os/shared.rs
@@ -123,7 +123,10 @@ pub fn get_input(
     let (on_winch, cleanup) = sigwinch();
     let dns_client = if resolve {
         let mut runtime = Runtime::new()?;
-        let resolver = runtime.block_on(dns::Resolver::new(runtime.handle().clone()))?;
+        let resolver = match runtime.block_on(dns::Resolver::new(runtime.handle().clone())) {
+            Ok(resolver) => resolver,
+            Err(_) => failure::bail!("Could not initialize the DNS resolver. Are you offline?"),
+        };
         let dns_client = dns::Client::new(resolver, runtime)?;
         Some(dns_client)
     } else {