returned a non-zero code: 1

The docker build process fails:

Step 1/11 : FROM golang:1.14.2-alpine as builder
---> dda4232b2bd5
Step 2/11 : ENV BURROW_SRC /usr/src/Burrow/
---> Using cache
---> d6936bdedad4
Step 3/11 : RUN apk add --no-cache git curl
---> Running in 887842344b6c
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz
(1/6) Installing nghttp2-libs (1.40.0-r0)
(2/6) Installing libcurl (7.67.0-r0)
(3/6) Installing curl (7.67.0-r0)
(4/6) Installing expat (2.2.9-r1)
(5/6) Installing pcre2 (10.34-r1)
(6/6) Installing git (2.24.3-r0)
Executing busybox-1.31.1-r9.trigger
OK: 22 MiB in 21 packages
Removing intermediate container 887842344b6c
---> c2417d7224c9
Step 4/11 : COPY . $BURROW_SRC
---> ef9a59918935
Step 5/11 : WORKDIR $BURROW_SRC
---> Running in 49e6f5c86958
Removing intermediate container 49e6f5c86958
---> 788cb7be68f4
Step 6/11 : RUN go mod tidy && go build -o /tmp/burrow .
---> Running in 30fd033472c2
go: cannot find main module; see 'go help modules'
The command '/bin/sh -c go mod tidy && go build -o /tmp/burrow .' returned a non-zero code: 1

Docker version 19.03.3, build a872fc2f86

Start by reproducing the Docker build and inspect the Docker build configuration around the Go module setup shown in the log. Verify the Go module is available during the build and confirm completion when the image builds successfully.

Written by the indexing model from the issue text.