Unconditionally set RUSTUP_TOOLCHAIN_SOURCE in proxy

Author: smoelius

src/cli/proxy_mode.rs

@@ -1,4 +1,7 @@
-use std::{path::PathBuf, process::ExitStatus};
+use std::{
+    path::PathBuf,
+    process::{Command, ExitStatus},
+};
 
 use anyhow::Result;
 
@@ -7,7 +10,7 @@ use crate::{
     command::run_command_for_dir,
     config::ActiveReason,
     process::Process,
-    toolchain::{ResolvableLocalToolchainName, maybe_set_env_source},
+    toolchain::ResolvableLocalToolchainName,
 };
 
 #[tracing::instrument(level = "trace", skip(process))]
@@ -36,8 +39,23 @@ pub async fn main(arg0: &str, current_dir: PathBuf, process: &Process) -> Result
     let cfg = set_globals(current_dir, true, process)?;
     let toolchain = cfg.resolve_local_toolchain(toolchain).await?;
     let mut cmd = toolchain.command(arg0)?;
-    if toolchain_specified {
-        maybe_set_env_source(&mut cmd, || Some(ActiveReason::CommandLine));
-    }
+    set_env_source(
+        &mut cmd,
+        if toolchain_specified {
+            Some(ActiveReason::CommandLine)
+        } else if let Ok(Some((_, reason))) = cfg.active_toolchain() {
+            Some(reason)
+        } else {
+            None
+        },
+    );
     run_command_for_dir(cmd, arg0, &cmd_args)
 }
+
+/// Set the `RUSTUP_TOOLCHAIN_SOURCE` environment variable to indicate how the toolchain was
+/// determined.
+fn set_env_source(cmd: &mut Command, reason: Option<ActiveReason>) {
+    if let Some(reason) = reason {
+        cmd.env("RUSTUP_TOOLCHAIN_SOURCE", reason.to_source());
+    }
+}

src/toolchain.rs

@@ -181,14 +181,6 @@ impl<'a> Toolchain<'a> {
 
         env_var::inc("RUST_RECURSION_COUNT", cmd, self.cfg.process);
 
-        maybe_set_env_source(cmd, || {
-            if let Ok(Some((_, reason))) = self.cfg.active_toolchain() {
-                Some(reason)
-            } else {
-                None
-            }
-        });
-
         cmd.env("RUSTUP_TOOLCHAIN", format!("{}", self.name));
         cmd.env("RUSTUP_HOME", &self.cfg.rustup_dir);
     }
@@ -613,16 +605,3 @@ impl<'a> Toolchain<'a> {
             .collect())
     }
 }
-
-/// Set the `RUSTUP_TOOLCHAIN_SOURCE` environment variable if not already set.
-///
-/// `RUSTUP_TOOLCHAIN_SOURCE` indicates how the toolchain was determined. The environment
-/// variable could have been set in proxy_mode.rs, in which case it should not be changed.
-pub(crate) fn maybe_set_env_source(cmd: &mut Command, f: impl FnOnce() -> Option<ActiveReason>) {
-    if env::var_os("RUSTUP_TOOLCHAIN_SOURCE").is_some() {
-        return;
-    }
-    if let Some(reason) = f() {
-        cmd.env("RUSTUP_TOOLCHAIN_SOURCE", reason.to_source());
-    }
-}