Using `docker buildx bake` to build a binary at a tagged commit ends up with a `X.Y.Z.m` version

[ericpromislow]

Description

When I build a CLI with the command docker builds bake --set binary.platform=X/amd64 (where X is darwin, linux, or windows) at the tag v20.10.9, running build/docker -v says 20.10.9.m. The .m is problematic.

Steps to reproduce the issue:

On a macos box, do the following:

cd /tmp
git clone -b v20.10.9 https://github.com/docker/cli.git
cd cli
docker buildx bake --set binary.platform=darwin/amd64
./build/docker -v

Describe the results you received:

20.1.9.m

Describe the results you expected:

20.1.9

Additional information you deem important (e.g. issue happens only occasionally):

I added git status near the top of scripts/build/.variables and got this output, which explains the problem:

#18 1.828 + git status
#18 2.068 HEAD detached at v20.10.9
#18 2.068 Changes not staged for commit:
#18 2.068   (use "git add/rm <file>..." to update what will be committed)
#18 2.068   (use "git restore <file>..." to discard changes in working directory)
#18 2.068 	deleted:    .circleci/config.yml
#18 2.068 	deleted:    .dockerignore
#18 2.068 	deleted:    .github/CODEOWNERS
#18 2.068 	deleted:    .github/ISSUE_TEMPLATE.md
#18 2.068 	deleted:    .github/PULL_REQUEST_TEMPLATE.md
#18 2.068 	deleted:    .github/workflows/codeql-analysis.yml
#18 2.068 	deleted:    .gitignore
#18 2.068 	deleted:    appveyor.yml
#18 2.068 	deleted:    cli/winresources/res_windows.go
#18 2.068 	modified:   scripts/build/.variables
#18 2.068
#18 2.068 no changes added to commit (use "git add" and/or "git commit -a")

Output of docker version:

Client:
 Cloud integration: 1.0.17
 Version:           20.10.8
 API version:       1.41
 Go version:        go1.16.6
 Git commit:        3967b7d
 Built:             Fri Jul 30 19:55:20 2021
 OS/Arch:           darwin/amd64
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.8
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.16.6
  Git commit:       75249d8
  Built:            Fri Jul 30 19:52:10 2021
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.4.9
  GitCommit:        e25210fe30a0a703442421b0f60afac609f950a3
 runc:
  Version:          1.0.1
  GitCommit:        v1.0.1-0-g4144b63
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

Output of docker info:

Client:
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Build with BuildKit (Docker Inc., v0.6.1-docker)
  compose: Docker Compose (Docker Inc., v2.0.0-rc.1)
  scan: Docker Scan (Docker Inc., v0.8.0)

Server:
 Containers: 30
  Running: 21
  Paused: 0
  Stopped: 9
 Images: 18
 Server Version: 20.10.8
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: e25210fe30a0a703442421b0f60afac609f950a3
 runc version: v1.0.1-0-g4144b63
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 5.10.47-linuxkit
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: 1.938GiB
 Name: docker-desktop
 ID: 73GC:37KA:5L75:IYDE:3WL2:LVCJ:L46N:77NZ:GN2W:CV76:NJSS:EPUW
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

This happens on a github action as well, on ubuntu. I don't know the version of docker they're running.

[crazy-max]

@ericpromislow Looks like an issue with .dockerignore (#3349). In the meantime you can use the VERSION env var:

VERSION=20.10.9 docker buildx bake --set binary.platform=darwin/amd64