fix stuff with bun_path

reflex/utils/path_ops.py

@@ -9,7 +9,7 @@
 from pathlib import Path
 
 from reflex import constants
-from reflex.config import environment
+from reflex.config import environment, get_config
 
 # Shorthand for join.
 join = os.linesep.join
@@ -187,6 +187,19 @@ def get_npm_path() -> Path | None:
     return npm_path.absolute() if npm_path else None
 
 
+def get_bun_path() -> Path | None:
+    """Get bun binary path.
+
+    Returns:
+        The path to the bun binary file.
+    """
+    bun_path = get_config().bun_path
+    if use_system_bun() or not bun_path.exists():
+        system_bun_path = which("bun")
+        bun_path = Path(system_bun_path) if system_bun_path else None
+    return bun_path.absolute() if bun_path else None
+
+
 def update_json_file(file_path: str | Path, update_dict: dict[str, int | str]):
     """Update the contents of a json file.
 

reflex/utils/prerequisites.py

@@ -194,10 +194,13 @@ def get_bun_version() -> version.Version | None:
     Returns:
         The version of bun.
     """
+    bun_path = path_ops.get_bun_path()
+    if bun_path is None:
+        return None
     try:
         # Run the bun -v command and capture the output
-        result = processes.new_process([str(get_config().bun_path), "-v"], run=True)
-        return version.parse(result.stdout)  # type: ignore
+        result = processes.new_process([str(bun_path), "-v"], run=True)
+        return version.parse(str(result.stdout))
     except FileNotFoundError:
         return None
     except version.InvalidVersion as e: