minishift: minishift start fails contacting Github to download oc

I’m encountering a really odd issue w/ a fresh minishift install on OSX w/ xhyve; when I minishift start, the oc download fails.

• Minishift version: minishift v1.17.0+f974f0c
• OS: macOS High Sierra 10.13.3
• Hypervisor: xhyve

Steps to reproduce

$ minishift start --show-libmachine-logs -v5
-- minishift version: v1.17.0+f974f0c
-- Starting profile 'minishift'
-- Checking if https://github.com is reachable ... FAIL
-- Checking if requested OpenShift version 'v3.9.0' is valid ... SKIP
-- Checking if requested OpenShift version 'v3.9.0' is supported ... OK
-- Checking if requested hypervisor 'xhyve' is supported on this platform ... OK
-- Checking if xhyve driver is installed ...
   Driver is available at /usr/local/bin/docker-machine-driver-xhyve
   Checking for setuid bit ... OK
-- Checking the ISO URL ... OK
Error starting the cluster: Error attempting to download and cache 'oc': Cannot get the OpenShift release version v3.9.0: Get https://api.github.com/repos/openshift/origin/releases/tags/v3.9.0: net/http: TLS handshake timeout

Github appears to be reachable:

$ curl -s "https://api.github.com/repos/openshift/origin/releases/tags/v3.9.0" | python -m json.tool | head -n5
{
    "assets": [
        {
            "browser_download_url": "https://github.com/openshift/origin/releases/download/v3.9.0/CHECKSUM",
            "content_type": "application/octet-stream",

Expected

oc is downloaded and minishift starts