x509: certificate signed by unknown authority

[mlevin2]

I'm getting this error on the Mac client:

ERROR CODE 1601 - API network error: doRetry failed, at tempts: 3, timeout 5.324s, last err: Get "https://api-0.core.keybaseapi.com/_/api/1.0/home.json?num_people=10O&record_visit=0": x509: certificate signed by unknown authority in method keybase. 1.home. homeGetScreen

I tried manually trusting the cert for api-0.core.keybaseapi.com in my keychain, but that didn't help. And since the client can't use the API, I was unable to submit feedback or logs there.