Cmd parsing error on Windows

[n1vk]

While using air to run delve, I edit cmd in .air.toml to have build flags.

cmd = "go build -gcflags='all=-N -l' -o ./tmp/main.exe"

However this would produce error:

invalid value "'all=-N" for flag -gcflags: parameter may not start with quote character '

After a bit looking into the codes, I found out it was because of using cmd /c. In runner/util_windows.go:24, we have

c := exec.Command("cmd", "/c", cmd)

You can run this on Windows and reproduce the bug:

cmd /c "go build -gcflags='all=-N -l' -o ./tmp/main.exe"

Maybe replacing cmd /c with powershell?

[n1vk]

Another issue is that air falls back to default config silently.

While I was looking for solutions, I changed -gcflags to use ", \' and \". It might be obvious that using " will cause parsing failure, but only when calling air -c .air.toml would produce the error.

Calling air should have explicit warning of not using local .air.toml. (Like #709)