fix(exec): respect PATH order for virtualenv resolution in mise x

e2e/cli/test_exec_venv_path_order

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+
+# Regression test: `mise x -- tool` should respect PATH order when a
+# virtualenv (or similar) directory is prepended to PATH by mise config.
+# Previously, `which_bin` pre-resolution bypassed PATH entirely for
+# mise-managed tools, so a venv binary would be ignored even though
+# mise itself added it to PATH.
+# See: https://github.com/jdx/mise/discussions/8340
+
+# Create a fake "venv" with a dummy override that prints a distinct marker
+venvdir="$HOME/fake_venv/bin"
+mkdir -p "$venvdir"
+cat >"$venvdir/dummy" <<'SCRIPT'
+#!/bin/sh
+echo VENV_DUMMY
+SCRIPT
+chmod +x "$venvdir/dummy"
+
+# Configure mise with the dummy tool and prepend the venv dir to PATH
+# (this simulates what _.python.venv does)
+cat >mise.toml <<EOF
+[tools]
+dummy = "latest"
+
+[env]
+_.path = ["$venvdir"]
+EOF
+
+mise i
+
+# mise x -- which dummy should find the venv binary first
+assert "mise x -- which dummy" "$venvdir/dummy"
+
+# mise x -- dummy should actually execute the venv binary, not the mise-managed one
+assert "mise x -- dummy" "VENV_DUMMY"

src/cli/exec.rs

@@ -126,25 +126,6 @@ impl Exec {
 
         let (program, mut args) = parse_command(&env::SHELL, &self.command, &self.c);
 
-        // On Unix, resolve the program to its full mise-installed path if it is
-        // provided by a mise-managed tool. This prevents infinite recursion when
-        // a wrapper script (e.g., .devcontainer/bin/tool) calls `mise x -- tool`:
-        // without this, execvp would find the wrapper again (since it precedes
-        // the mise install path in PATH) and loop until E2BIG.
-        // On Windows, exec_program uses which::which_in with PATHEXT to resolve
-        // the correct executable (.cmd/.exe), so we skip this to avoid passing
-        // a pre-resolved path that bypasses Windows-specific extension handling.
-        #[cfg(unix)]
-        let program = if !program.contains('/') {
-            if let Some(bin) = ts.which_bin(&config, &program).await {
-                bin.to_string_lossy().to_string()
-            } else {
-                program
-            }
-        } else {
-            program
-        };
-
         let mut env = measure!("env_with_path", { ts.env_with_path(&config).await? });
 
         // Run auto-enabled prepare steps (unless --no-prepare)