Can "--host" related command information be deleted?

[heisen-li]

I found that in 2017 "--host" has been replaced by "--index". #4209

Is it necessary to keep this command or prompt message now?

cargo/tests/testsuite/search.rs

Lines 184 to 236 in 7f08ace

	// TODO: Deprecated
	// remove once it has been decided '--host' can be safely removed
	#[cargo_test]
	fn simple_with_host() {
	setup();
	cargo_process("search postgres --host")
	.arg(registry_url().to_string())
	.with_stderr(
	"\
	[WARNING] The flag '--host' is no longer valid.
	Previous versions of Cargo accepted this flag, but it is being
	deprecated. The flag is being renamed to 'index', as the flag
	wants the location of the index. Please use '--index' instead.
	This will soon become a hard error, so it's either recommended
	to update to a fixed version or contact the upstream maintainer
	about this warning.
	[UPDATING] `[CWD]/registry` index
	",
	)
	.with_stdout_contains(SEARCH_RESULTS)
	.run();
	}
	// TODO: Deprecated
	// remove once it has been decided '--host' can be safely removed
	#[cargo_test]
	fn simple_with_index_and_host() {
	setup();
	cargo_process("search postgres --index")
	.arg(registry_url().to_string())
	.arg("--host")
	.arg(registry_url().to_string())
	.with_stderr(
	"\
	[WARNING] The flag '--host' is no longer valid.
	Previous versions of Cargo accepted this flag, but it is being
	deprecated. The flag is being renamed to 'index', as the flag
	wants the location of the index. Please use '--index' instead.
	This will soon become a hard error, so it's either recommended
	to update to a fixed version or contact the upstream maintainer
	about this warning.
	[UPDATING] `[CWD]/registry` index
	",
	)
	.with_stdout_contains(SEARCH_RESULTS)
	.run();
	}

and
https://github.com/rust-lang/cargo/blob/7f08ace4f1/src/cargo/util/command_prelude.rs#L633

[alexcrichton]

Our policy on removing features is to first confirm that they have been warning for a long time, and only if the warning has been issued then it's safe to remove at this point.

[heisen-li]

I think it has been reminded long enough. Do you mean that there is still a need to issue a warning to remove the feature? What to do next?

[alexcrichton]

If the warning has been issued for years then it should be safe to remove, yes.