But that doesn’t preclude mistakes by collision (N short flags match a long one) or unpredictable bugs in a long flag interpreter (a short flag being a substring of a long one)—both being trivially common bugs when this ambiguity is allowed, especially when an API is ported to another environment with less tooling standardization around interpreting the input.
Go doesn't allow for specifying multiple short flags all run together, or for flag args without spaces, so neither of those are directly relevant here.
Also, that first issue happens with POSIX flags (with the GNU long flag extension, anyhow): `grep -help` is different from `grep --help` (and if you type the former, it'll just wait patiently for you to close stdin).
