Travis: Could not resolve host: ftp.netbsd.org

[nagisa]

Spurious failure:

+ cd ../..
+ rm -rf binutils
+ mkdir netbsd
+ curl https://ftp.netbsd.org/pub/NetBSD/NetBSD-7.0/amd64/binary/sets/base.tgz
+ tar xzf - -C netbsd  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0 ./usr/include ./usr/lib ./lib
  0     0    0     0    0     0      0      0 --:--:--  0:00:02 --:--:--     0curl: (6) Could not resolve host: ftp.netbsd.org
gzip: stdin: unexpected end of file
tar: Child returned status 1
tar: Error is not recoverable: exiting now
The command '/bin/sh -c sh /tmp/build-toolchain.sh' returned a non-zero code: 2

Needs some retries here as well cc @alexcrichton

https://travis-ci.org/rust-lang/rust/builds/192387934

[Mark-Simulacrum]

I'm also seeing problems when resolving with what I assume is my ISP's DNS server, but little to no problems resolving with Google's 8.8.8.8 DNS. Maybe we could configure Travis to use that? This could be (and I assume it is) a temporary malfunction.

[nagisa]

We also should NOT be hitting the netbsd’s poor ftp server with every single build for 50MB of data.