address comments

doc/src/basics.md

@@ -30,14 +30,15 @@ info: downloading self-updates
 
 ## Keeping `rustup` up to date
 
-If your `rustup` build with the `no-self-update` feature, it will not be able to update itself.
+If your `rustup` was build with the `no-self-update` feature, it will not be able to update itself.
+`rustup` does not use this feature by default, including the rustups you downloaded from https://rustup.rs.
 
-If your `rustup` build without the `no-self-update` feature, 
+If your `rustup` was build without the `no-self-update` feature, 
 it is possible to control Rustup's automatic self update mechanism with the `auto-self-update` configuration variable. 
 This setting supports three values: `enable` and `disable` and `check-only`.
 
 * `disable` will ensure that no automatic self updating actions are taken.
-* `enable` will mean that `rustup update` and similar commands will also check-for, and install, any update to Rustup.
+* `enable` will mean that `rustup update` and similar commands will also check for, and install, any update to Rustup.
 * `check-only` will cause any automatic self update to check and report on any updates, but not to automatically install them.
 
 Whether `auto-self-update` is `enable` or not, you can request that Rustup check for, and update itself to the
@@ -50,7 +51,7 @@ info: checking for self-updates
 info: downloading self-updates
 ```
 
-> ### Disable automatic self-updates with the parameter of the command
+### Disable automatic self-updates with the parameter of the command
 > Since the default value of auto-self-update is `enable`, `rustup` will automatically update itself at the end of any
 > toolchain installation as well.  You can prevent this automatic behaviour by
 > passing the `--no-self-update` argument when running `rustup update` or

src/cli/errors.rs

@@ -13,6 +13,8 @@ use thiserror::Error as ThisError;
 pub enum CLIError {
     #[error("couldn't determine self executable name")]
     NoExeName,
+    #[error("couldn't determine self executable file path")]
+    NoExeFilePath,
     #[error("rustup is not installed at '{}'", .p.display())]
     NotSelfInstalled { p: PathBuf },
     #[error("failure reading directory {}", .p.display())]

src/cli/rustup_mode.rs

@@ -17,6 +17,7 @@ use super::{
     common,
     self_update::{check_rustup_update, SelfUpdateMode},
 };
+use crate::cli::errors::CLIError;
 use crate::dist::dist::{
     PartialTargetTriple, PartialToolchainDesc, Profile, TargetTriple, ToolchainDesc,
 };
@@ -1587,7 +1588,10 @@ fn set_profile(cfg: &mut Cfg, m: &ArgMatches<'_>) -> Result<utils::ExitCode> {
 
 fn set_auto_self_update(cfg: &mut Cfg, m: &ArgMatches<'_>) -> Result<utils::ExitCode> {
     if self_update::NEVER_SELF_UPDATE {
-        warn!("{} is built with the no-self-update feature: setting auto-self-update will not have any effect.",cfg.rustup_dir.display());
+        let mut args = crate::process().args_os();
+        let arg0 = args.next().map(PathBuf::from);
+        let arg0 = arg0.as_ref().and_then(|a| a.to_str());
+        warn!("{} is built with the no-self-update feature: setting auto-self-update will not have any effect.",arg0.ok_or(CLIError::NoExeFilePath)?);
     }
     cfg.set_auto_self_update(&m.value_of("auto-self-update-mode").unwrap())?;
     Ok(utils::ExitCode(0))

src/cli/self_update.rs

@@ -125,12 +125,12 @@ impl FromStr for SelfUpdateMode {
 
 impl ToString for SelfUpdateMode {
     fn to_string(&self) -> String {
-        let modes = Self::modes();
         match self {
-            SelfUpdateMode::Enable => modes[0].to_string(),
-            SelfUpdateMode::Disable => modes[1].to_string(),
-            SelfUpdateMode::CheckOnly => modes[2].to_string(),
+            SelfUpdateMode::Enable => "enable",
+            SelfUpdateMode::Disable => "disable",
+            SelfUpdateMode::CheckOnly => "check-only",
         }
+        .into()
     }
 }
 

src/settings.rs

@@ -91,7 +91,7 @@ impl Default for Settings {
             profile: Some("default".to_owned()),
             overrides: BTreeMap::new(),
             pgp_keys: None,
-            auto_self_update: Some(SelfUpdateMode::Enable),
+            auto_self_update: None,
         }
     }
 }