Made some errors non-fatal.

Author: sollyucko

src/cli/common.rs

@@ -522,3 +522,17 @@ pub fn report_error(e: &Error) {
         }
     }
 }
+
+pub fn ignorable_error(error: crate::errors::Error, no_prompt: bool) -> Result<()> {
+    report_error(&error);
+    if no_prompt {
+        warn!("continuing (because the -y flag is set and the error is ignorable)");
+        Ok(())
+    } else {
+        if confirm("\nContinue? (y/N)", false).unwrap_or(false) {
+            Ok(())
+        } else {
+            Err(error)
+        }
+    }
+}

src/cli/self_update.rs

@@ -30,7 +30,7 @@
 //! Deleting the running binary during uninstall is tricky
 //! and racy on Windows.
 
-use crate::common::{self, Confirm};
+use crate::common::{self, ignorable_error, Confirm};
 use crate::errors::*;
 use crate::markdown::md;
 use crate::term2;
@@ -235,7 +235,7 @@ fn canonical_cargo_home() -> Result<String> {
 /// `CARGO_HOME`/bin, hard-linking the various Rust tools to it,
 /// and adding `CARGO_HOME`/bin to PATH.
 pub fn install(no_prompt: bool, verbose: bool, quiet: bool, mut opts: InstallOpts) -> Result<()> {
-    do_pre_install_sanity_checks()?;
+    do_pre_install_sanity_checks(no_prompt)?;
     do_pre_install_options_sanity_checks(&opts)?;
     check_existence_of_rustc_or_cargo_in_path(no_prompt)?;
     #[cfg(unix)]
@@ -378,8 +378,8 @@ fn check_existence_of_rustc_or_cargo_in_path(no_prompt: bool) -> Result<()> {
     // Only the test runner should set this
     let skip_check = env::var_os("RUSTUP_INIT_SKIP_PATH_CHECK");
 
-    // Ignore this check if called with no prompt (-y) or if the environment variable is set
-    if no_prompt || skip_check == Some("yes".into()) {
+    // Skip this if the environment variable is set
+    if skip_check == Some("yes".into()) {
         return Ok(());
     }
 
@@ -390,13 +390,12 @@ fn check_existence_of_rustc_or_cargo_in_path(no_prompt: bool) -> Result<()> {
         err!("Otherwise you may have confusion unless you are careful with your PATH");
         err!("If you are sure that you want both rustup and your already installed Rust");
         err!("then please restart the installation and pass `-y' to bypass this check.");
-        Err("cannot install while Rust is installed".into())
-    } else {
-        Ok(())
+        ignorable_error("cannot install while Rust is installed".into(), no_prompt)?;
     }
+    Ok(())
 }
 
-fn do_pre_install_sanity_checks() -> Result<()> {
+fn do_pre_install_sanity_checks(no_prompt: bool) -> Result<()> {
     let rustc_manifest_path = PathBuf::from("/usr/local/lib/rustlib/manifest-rustc");
     let uninstaller_path = PathBuf::from("/usr/local/lib/rustlib/uninstall.sh");
     let rustup_sh_path = utils::home_dir().unwrap().join(".rustup");
@@ -412,7 +411,7 @@ fn do_pre_install_sanity_checks() -> Result<()> {
             "run `{}` as root to uninstall Rust",
             uninstaller_path.display()
         );
-        // return Err("cannot install while Rust is installed".into());
+        ignorable_error("cannot install while Rust is installed".into(), no_prompt)?;
     }
 
     if rustup_sh_exists {
@@ -422,7 +421,10 @@ fn do_pre_install_sanity_checks() -> Result<()> {
         warn!("or, if you already have rustup installed, you can run");
         warn!("`rustup self update` and `rustup toolchain list` to upgrade");
         warn!("your directory structure");
-        return Err("cannot install while rustup.sh is installed".into());
+        ignorable_error(
+            "cannot install while rustup.sh is installed".into(),
+            no_prompt,
+        )?;
     }
 
     Ok(())