os/exec: pass more than 1 ldflags

[pjebs]

I'm using Go 1.10 in windows:

For some reason it appears as if -ldflags doesn't allow combining flags when used with exec.CommandContext.

cmd = exec.CommandContext(ctx, "go", "build", "-o", outputPath, "-ldflags=-s", "-ldflags=-w", "-ldflags \"-H windowsgui\"", goFilePath)
cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%s", "GOOS", "windows"))

cmd.CombinedOutput()

The later ldflag flag seems to overwrite the prior.

[ianlancetaylor]

That's how cmd/go works. You pass a single -ldflags option, not multiple ones. That is true on the command and line and it is true when using exec.CommandContext. See the discussion of ldflags and friends at https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies .

[pjebs]

https://lukeeckley.com/post/useful-go-build-flags/
https://blog.alexellis.io/inject-build-time-vars-golang/