Subject: "updating substitutes" spam

From: Taylan Kammer <[email-masked]>
Date: Sun, 02 Dec 2018 14:09:17 +0100

A minor issue, but I wanted to create a bug-report for this to make
sure it's on the radar.

During updates, guix may print this message hundreds of times:

    substitute: updating substitutes from 'http://...' 100%

Repetitions of this message should probably be coalesced into a single
message.

- Taylan