go.mod not build by Dockerfile

[leifnel]

Just tried building the Dockerfile.

root@machine:/home# docker build certdumper
Sending build context to Docker daemon  3.584kB
Step 1/12 : FROM golang:1-alpine as builder
1-alpine: Pulling from library/golang
9d48c3bd43c5: Already exists
7f94eaf8af20: Pull complete
9fe9984849c1: Pull complete
43c4d47973b8: Pull complete
9aaad45c37b5: Pull complete
Digest: sha256:84349ee862d8bafff35e0d2bfd539da565b536b4dfce654773fc21a1db2da6d7
Status: Downloaded newer image for golang:1-alpine
 ---> 33fbbc2ca571
Step 2/12 : RUN apk --update upgrade     && apk --no-cache --no-progress add git make gcc musl-dev
 ---> Running in d3597d5eeba1
fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/community/x86_64/APKINDEX.tar.gz
(1/2) Upgrading libcrypto1.1 (1.1.1c-r0 -> 1.1.1d-r0)
(2/2) Upgrading libssl1.1 (1.1.1c-r0 -> 1.1.1d-r0)
Executing ca-certificates-20190108-r0.trigger
OK: 6 MiB in 15 packages
fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/community/x86_64/APKINDEX.tar.gz
(1/17) Installing binutils (2.32-r0)
(2/17) Installing gmp (6.1.2-r1)
(3/17) Installing isl (0.18-r0)
(4/17) Installing libgomp (8.3.0-r0)
(5/17) Installing libatomic (8.3.0-r0)
(6/17) Installing libgcc (8.3.0-r0)
(7/17) Installing mpfr3 (3.1.5-r1)
(8/17) Installing mpc1 (1.1.0-r0)
(9/17) Installing libstdc++ (8.3.0-r0)
(10/17) Installing gcc (8.3.0-r0)
(11/17) Installing nghttp2-libs (1.39.2-r0)
(12/17) Installing libcurl (7.65.1-r0)
(13/17) Installing expat (2.2.7-r1)
(14/17) Installing pcre2 (10.33-r0)
(15/17) Installing git (2.22.0-r0)
(16/17) Installing make (4.2.1-r2)
(17/17) Installing musl-dev (1.1.22-r3)
Executing busybox-1.30.1-r2.trigger
OK: 118 MiB in 32 packages
Removing intermediate container d3597d5eeba1
 ---> e7522d5a71b3
Step 3/12 : WORKDIR /go/src/github.com/ldez/traefik-certs-dumper
 ---> Running in 9046c9f90ea6
Removing intermediate container 9046c9f90ea6
 ---> 18738efae570
Step 4/12 : ENV GO111MODULE on
 ---> Running in dba1b77b77ac
Removing intermediate container dba1b77b77ac
 ---> c9d456560990
Step 5/12 : COPY go.mod go.sum ./
COPY failed: stat /var/lib/docker/tmp/docker-builder498622939/go.mod: no such file or directory

[leifnel]

My error.