Convert early exits into errors

Author: tuguzT

crates/cargo-gpu-cache/src/install_toolchain.rs

@@ -3,8 +3,6 @@
 use anyhow::Context as _;
 use crossterm::tty::IsTty as _;
 
-use crate::user_output;
-
 /// Use `rustup` to install the toolchain and components, if not already installed.
 ///
 /// Pretty much runs:
@@ -108,10 +106,8 @@ fn get_consent_for_toolchain_install(
     }
 
     if !std::io::stdout().is_tty() {
-        user_output!("No TTY detected so can't ask for consent to install Rust toolchain.")?;
         log::error!("Attempted to ask for consent when there's no TTY");
-        #[expect(clippy::exit, reason = "can't ask for user consent if there's no TTY")]
-        std::process::exit(1);
+        anyhow::bail!("no TTY detected, so can't ask for consent to install Rust toolchain")
     }
 
     log::debug!("asking for consent to install the required toolchain");
@@ -138,8 +134,6 @@ fn get_consent_for_toolchain_install(
     {
         Ok(())
     } else {
-        crate::user_output!("Exiting...\n")?;
-        #[expect(clippy::exit, reason = "user requested abort")]
-        std::process::exit(0);
+        anyhow::bail!("user denied to install the required toolchain\n");
     }
 }

crates/cargo-gpu-cache/src/lockfile.rs

@@ -188,7 +188,27 @@ impl LockfileMismatchHandler {
         is_force_overwrite_lockfiles_v4_to_v3: bool,
     ) -> anyhow::Result<()> {
         if !is_force_overwrite_lockfiles_v4_to_v3 {
-            Self::exit_with_v3v4_hack_suggestion();
+            #[expect(clippy::needless_raw_strings, reason = "false positive")]
+            const V3V4_HACK_SUGGESTION: &str = r"
+Because `cargo gpu` uses a dedicated Rust toolchain for compiling shaders,
+it's possible that the `Cargo.lock` manifest version of the shader crate
+does not match the `Cargo.lock` manifest version of the workspace.
+This is due to a change in the defaults introduced in Rust 1.83.0.
+
+One way to resolve this is to force the workspace to use the same version
+of Rust as required by the shader. However, that is not often ideal or even
+possible. Another way is to exclude the shader from the workspace. This is
+also not ideal if you have many shaders sharing config from the workspace.
+
+Therefore, `cargo gpu build/install` offers a workaround with the argument:
+  --force-overwrite-lockfiles-v4-to-v3
+
+See `cargo gpu build --help` for more information.
+";
+            #[expect(clippy::non_ascii_literal, reason = "this character is really needed")]
+            {
+                anyhow::bail!("conflicting `Cargo.lock` versions detected ⚠️{V3V4_HACK_SUGGESTION}")
+            }
         }
 
         Self::replace_cargo_lock_manifest_version(offending_cargo_lock, "4", "3")
@@ -237,32 +257,6 @@ impl LockfileMismatchHandler {
 
         Ok(())
     }
-
-    /// Exit and give the user advice on how to deal with the infamous
-    /// v3/v4 Cargo lockfile version problem.
-    #[expect(clippy::unwrap_used, reason = "It's CLI output")]
-    fn exit_with_v3v4_hack_suggestion() {
-        crate::user_output!(
-            "Conflicting `Cargo.lock` versions detected ⚠️\n\
-            Because `cargo gpu` uses a dedicated Rust toolchain for compiling shaders\n\
-            it's possible that the `Cargo.lock` manifest version of the shader crate\n\
-            does not match the `Cargo.lock` manifest version of the workspace. This is\n\
-            due to a change in the defaults introduced in Rust 1.83.0.\n\
-            \n\
-            One way to resolve this is to force the workspace to use the same version\n\
-            of Rust as required by the shader. However that is not often ideal or even\n\
-            possible. Another way is to exclude the shader from the workspace. This is\n\
-            also not ideal if you have many shaders sharing config from the workspace.\n\
-            \n\
-            Therefore `cargo gpu build/install` offers a workaround with the argument:\n\
-              --force-overwrite-lockfiles-v4-to-v3\n\
-            \n\
-            See `cargo gpu build --help` for more information.\n\
-            "
-        )
-        .unwrap();
-        std::process::exit(1);
-    }
 }
 
 impl Drop for LockfileMismatchHandler {

crates/cargo-gpu/src/main.rs

@@ -24,7 +24,7 @@ fn main() -> ExitCode {
             reason = "Our central place for outputting error messages"
         )]
         {
-            eprintln!("Error: {error}");
+            eprintln!("Error: {}", error.root_cause());
             return ExitCode::FAILURE;
         };
     }