Update post install message to show only the source methods that are relevant to your system.

src/cli/self_update.rs

@@ -445,36 +445,20 @@ but will not be added automatically."
     };
 }
 
-#[cfg(not(windows))]
-macro_rules! post_install_msg_unix_source_env {
-    () => {
-        r#"To configure your current shell, you need to source
-the corresponding `env` file under {cargo_home}.
-
-This is usually done by running one of the following (note the leading DOT):
-    . "{cargo_home}/env"            # For sh/bash/zsh/ash/dash/pdksh
-    source "{cargo_home}/env.fish"  # For fish
-    source "{cargo_home_nushell}/env.nu"  # For nushell
-    source "{cargo_home}/env.tcsh"  # For tcsh
-    . "{cargo_home}/env.ps1"        # For pwsh
-    source "{cargo_home}/env.xsh"   # For xonsh
-"#
-    };
-}
-
 #[cfg(not(windows))]
 macro_rules! post_install_msg_unix {
     () => {
-        concat!(
-            r"# Rust is installed now. Great!
+        r"# Rust is installed now. Great!
 
 To get started you may need to restart your current shell.
 This would reload your `PATH` environment variable to include
 Cargo's bin directory ({cargo_home}/bin).
 
-",
-            post_install_msg_unix_source_env!(),
-        )
+To configure your current shell, you need to source
+the corresponding `env` file under {cargo_home}.
+
+This is usually done by running one of the following (note the leading DOT):
+{source_env_lines}"
     };
 }
 
@@ -494,15 +478,16 @@ Cargo's bin directory ({cargo_home}\\bin).
 #[cfg(not(windows))]
 macro_rules! post_install_msg_unix_no_modify_path {
     () => {
-        concat!(
-            r"# Rust is installed now. Great!
+        r"# Rust is installed now. Great!
 
 To get started you need Cargo's bin directory ({cargo_home}/bin) in your `PATH`
 environment variable. This has not been done automatically.
 
-",
-            post_install_msg_unix_source_env!(),
-        )
+To configure your current shell, you need to source
+the corresponding `env` file under {cargo_home}.
+
+This is usually done by running one of the following (note the leading DOT):
+{source_env_lines}"
     };
 }
 
@@ -661,19 +646,19 @@ pub(crate) async fn install(
         format!(post_install_msg_win!(), cargo_home = cargo_home)
     };
     #[cfg(not(windows))]
-    let cargo_home_nushell = Nu.cargo_home_str(cfg.process)?;
+    let source_env_lines = shell::build_source_env_lines(cfg.process);
     #[cfg(not(windows))]
     let msg = if no_modify_path {
         format!(
             post_install_msg_unix_no_modify_path!(),
             cargo_home = cargo_home,
-            cargo_home_nushell = cargo_home_nushell,
+            source_env_lines = source_env_lines,
         )
     } else {
         format!(
             post_install_msg_unix!(),
             cargo_home = cargo_home,
-            cargo_home_nushell = cargo_home_nushell,
+            source_env_lines = source_env_lines,
         )
     };
     md(&mut term, msg);

src/cli/self_update/shell.rs

@@ -73,6 +73,30 @@ fn enumerate_shells() -> Vec<Shell> {
     ]
 }
 
+/// Builds the shell source lines for the post-install message, showing only
+/// shells that are available on the current system. Shells sharing the same
+/// env file are grouped onto one line (e.g. sh/bash/zsh all use `env`).
+pub(crate) fn build_source_env_lines(process: &Process) -> String {
+    let mut groups = Vec::<(String, Vec<&'static str>)>::new();
+    for shell in get_available_shells(process) {
+        let Ok(src) = shell.source_string(process) else {
+            continue;
+        };
+        if let Some(names) = groups
+            .iter_mut()
+            .find_map(|(s, names)| (*s == src).then_some(names))
+        {
+            names.push(shell.name());
+        } else {
+            groups.push((src, vec![shell.name()]));
+        }
+    }
+    groups
+        .into_iter()
+        .map(|(src, names)| format!("    {}  # For {}\n", src, names.join("/")))
+        .collect()
+}
+
 pub(crate) fn get_available_shells(process: &Process) -> impl Iterator<Item = Shell> + '_ {
     enumerate_shells()
         .into_iter()
@@ -84,6 +108,9 @@ pub(crate) trait UnixShell {
     // heuristic should be used, assuming shells exist if any traces do.
     fn does_exist(&self, process: &Process) -> bool;
 
+    // Returns the display name of the shell, used in post-install messages.
+    fn name(&self) -> &'static str;
+
     // Gives all rcfiles of a given shell that Rustup is concerned with.
     // Used primarily in checking rcfiles for cleanup.
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf>;
@@ -128,6 +155,10 @@ impl UnixShell for Posix {
         true
     }
 
+    fn name(&self) -> &'static str {
+        "sh/ash/dash/pdksh"
+    }
+
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf> {
         match process.home_dir() {
             Some(dir) => vec![dir.join(".profile")],
@@ -149,6 +180,10 @@ impl UnixShell for Bash {
         !self.update_rcs(process).is_empty()
     }
 
+    fn name(&self) -> &'static str {
+        "bash"
+    }
+
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf> {
         // Bash also may read .profile, however Rustup already includes handling
         // .profile as part of POSIX and always does setup for POSIX shells.
@@ -197,6 +232,10 @@ impl UnixShell for Zsh {
             || utils::find_cmd(&["zsh"], process).is_some()
     }
 
+    fn name(&self) -> &'static str {
+        "zsh"
+    }
+
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf> {
         [Zsh::zdotdir(process).ok(), process.home_dir()]
             .iter()
@@ -229,6 +268,10 @@ impl UnixShell for Fish {
             || utils::find_cmd(&["fish"], process).is_some()
     }
 
+    fn name(&self) -> &'static str {
+        "fish"
+    }
+
     // > "$XDG_CONFIG_HOME/fish/conf.d" (or "~/.config/fish/conf.d" if that variable is unset) for the user
     // from <https://github.com/fish-shell/fish-shell/issues/3170#issuecomment-228311857>
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf> {
@@ -278,6 +321,10 @@ impl UnixShell for Nu {
             || utils::find_cmd(&["nu"], process).is_some()
     }
 
+    fn name(&self) -> &'static str {
+        "nushell"
+    }
+
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf> {
         let mut paths = vec![];
 
@@ -329,6 +376,10 @@ impl UnixShell for Tcsh {
             || utils::find_cmd(&["tcsh"], process).is_some()
     }
 
+    fn name(&self) -> &'static str {
+        "tcsh"
+    }
+
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf> {
         let mut paths = vec![];
 
@@ -378,6 +429,10 @@ impl UnixShell for Pwsh {
             || utils::find_cmd(&["pwsh"], process).is_some()
     }
 
+    fn name(&self) -> &'static str {
+        "pwsh"
+    }
+
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf> {
         let mut paths = vec![];
 
@@ -453,6 +508,10 @@ impl UnixShell for Xonsh {
         process.var("XONSHRC").is_ok() || utils::find_cmd(&["xonsh"], process).is_some()
     }
 
+    fn name(&self) -> &'static str {
+        "xonsh"
+    }
+
     fn rcfiles(&self, process: &Process) -> Vec<PathBuf> {
         let mut paths = vec![];