-compiler flag is ignored in binding generation

[xtrafrancyz]

Description

Command wails build -compiler go1.20.12 fails to complete when default go version installed is 1.21. The reason is binding generation process where there is no compiler setting. Go 1.21 forcibly adds line toolchain go1.21.5 to go.mod file and it becomes broken for 1.20.

wails/v2/pkg/commands/bindings/bindings.go

Lines 48 to 55 in aa8cd7c

	if options.GoModTidy {
	stdout, stderr, err = shell.RunCommand(workingDirectory, "go", "mod", "tidy")
	if err != nil {
	return stdout, fmt.Errorf("%s\n%s\n%s", stdout, stderr, err)
	}
	}
	stdout, stderr, err = shell.RunCommand(workingDirectory, "go", "build", "-tags", tagString, "-o", filename)

It would also be nice for wails dev to support -compiler flag to avoid manual editing go.mod for release build.

To Reproduce

1. Install latest Go version (1.21) globally
2. Install Go 1.20 https://go.dev/doc/manage-install (go install golang.org/dl/go1.20.12@latest, go1.20.12 download)
3. Create Wails project wails init
4. Remove toolchain 1.21.x from go.mod and change version to go 1.20
5. Run wails build -compiler go1.20.12

Error output:

go.mod:5: unknown directive: toolchain
  ERROR   exit status 1

Expected behaviour

Compilation successful with Go 1.20

Screenshots

No response

Attempted Fixes

Workaround: wails build -compiler go1.20.12 -skipbindings and edit go.mod every time before build.

System Details

# Wails
Version | v2.7.1

# System
┌───────────────────────────────────────────────────────────────────────────────────────────┐
| OS           | Windows 10 Home Single Language                                            |
| Version      | 2009 (Build: 22621)                                                        |
| ID           | 22H2                                                                       |
| Go Version   | go1.21.5                                                                   |
| Platform     | windows                                                                    |
| Architecture | amd64                                                                      |
| CPU          | Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz                                  |
| GPU 1        | NVIDIA GeForce MX350 (NVIDIA) - Driver: 31.0.15.3203                       |
| GPU 2        | Intel(R) Iris(R) Plus Graphics (Intel Corporation) - Driver: 31.0.101.2114 |
| Memory       | 16GB                                                                       |
└───────────────────────────────────────────────────────────────────────────────────────────┘

# Dependencies
┌───────────────────────────────────────────────────────┐
| Dependency | Package Name | Status    | Version       |
| WebView2   | N/A          | Installed | 120.0.2210.61 |
| Nodejs     | N/A          | Installed | 20.10.0       |
| npm        | N/A          | Installed | 10.2.3        |
| *upx       | N/A          | Installed | upx 4.2.1     |
| *nsis      | N/A          | Installed | v3.08         |
└─────────────── * - Optional Dependency ───────────────┘

Additional context

Compilation with 1.20 is needed for Windows 7, although there is no official support, but it works

[leaanthony]

Great idea. Happy to accept a PR for this 👍