So I wanted to set the number of jobs that the Rust compiler uses, and I heard it should go in config.toml. Furthermore config.toml should be in:
$CARGO_HOME/config.toml which defaults to:
Windows: %USERPROFILE%\.cargo\config.toml
Unix: $HOME/.cargo/config.toml
The closest things I have are three files names like this:
/home/myname/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/cfg-expr-0.15.8/.cargo/config.toml
That's not the one right? My understanding is that Cargo looks for a config.toml in the current directory and then recursively up one folder until it reaches root. I don't even know what it's using as I don't see a file named config.toml, and anyway the system-wide search only showed what I pasted above. Where is this config.toml file? Two of the config.toml files are really small that set a couple of flags, and then the one under cfg-expr-0.15.8/.cargo looks like:
[target.'cfg(all())']
rustflags = [
# BEGIN - Embark standard lints v6 for Rust 1.55+
# do not change or add/remove here, but one can add exceptions after this section
# for more info see: <https://github.com/EmbarkStudios/rust-ecosystem/issues/59>
"-Dunsafe_code",
"-Wclippy::all",
"-Wclippy::await_holding_lock",
"-Wclippy::char_lit_as_u8",
"-Wclippy::checked_conversions",
"-Wclippy::dbg_macro",
"-Wclippy::debug_assert_with_mut_call",
"-Wclippy::doc_markdown",
"-Wclippy::empty_enum",
"-Wclippy::enum_glob_use",
"-Wclippy::exit",
"-Wclippy::expl_impl_clone_on_copy",
"-Wclippy::explicit_deref_methods",
"-Wclippy::explicit_into_iter_loop",
"-Wclippy::fallible_impl_from",
"-Wclippy::filter_map_next",
"-Wclippy::flat_map_option",
"-Wclippy::float_cmp_const",
"-Wclippy::fn_params_excessive_bools",
"-Wclippy::from_iter_instead_of_collect",
"-Wclippy::if_let_mutex",
"-Wclippy::implicit_clone",
"-Wclippy::imprecise_flops",
"-Wclippy::inefficient_to_string",
"-Wclippy::invalid_upcast_comparisons",
"-Wclippy::large_digit_groups",
"-Wclippy::large_stack_arrays",
"-Wclippy::large_types_passed_by_value",
"-Wclippy::let_unit_value",
"-Wclippy::linkedlist",
"-Wclippy::lossy_float_literal",
"-Wclippy::macro_use_imports",
"-Wclippy::manual_ok_or",
"-Wclippy::map_err_ignore",
"-Wclippy::map_flatten",
"-Wclippy::map_unwrap_or",
"-Wclippy::match_on_vec_items",
"-Wclippy::match_same_arms",
"-Wclippy::match_wild_err_arm",
"-Wclippy::match_wildcard_for_single_variants",
"-Wclippy::mem_forget",
"-Wclippy::mismatched_target_os",
"-Wclippy::missing_enforced_import_renames",
"-Wclippy::mut_mut",
"-Wclippy::mutex_integer",
"-Wclippy::needless_borrow",
"-Wclippy::needless_continue",
"-Wclippy::needless_for_each",
"-Wclippy::option_option",
"-Wclippy::path_buf_push_overwrite",
"-Wclippy::ptr_as_ptr",
"-Wclippy::rc_mutex",
"-Wclippy::ref_option_ref",
"-Wclippy::rest_pat_in_fully_bound_structs",
"-Wclippy::same_functions_in_if_condition",
"-Wclippy::semicolon_if_nothing_returned",
"-Wclippy::single_match_else",
"-Wclippy::string_add_assign",
"-Wclippy::string_add",
"-Wclippy::string_lit_as_bytes",
"-Wclippy::string_to_string",
"-Wclippy::todo",
"-Wclippy::trait_duplication_in_bounds",
"-Wclippy::unimplemented",
"-Wclippy::unnested_or_patterns",
"-Wclippy::unused_self",
"-Wclippy::useless_transmute",
"-Wclippy::verbose_file_reads",
"-Wclippy::zero_sized_map_values",
"-Wfuture_incompatible",
"-Wnonstandard_style",
"-Wrust_2018_idioms",
# END - Embark standard lints v6 for Rust 1.55+
Edit: OK, I've discovered that Cargo also looks for files just named "config" without the ".toml", well in my cargo home there's no config file, only a bunch of "config.yml" and "config.rs", along with the three "config.toml" that I mentioned, but isn't in the cargo home folder, it's in some long-winded path down.
The "config.toml" file in your home path (plus ".cargo") is optional.
If you don't have one and you want to set some option, you simply create one.