idf_tool: fix unicode decode error

Closes https://github.com/espressif/esp-idf/issues/3841

diff --git a/tools/idf_tools.py b/tools/idf_tools.py
index 9ad9f019d2c0db0257af26bc271152429acf530f..3d2341237192981a84c5dc445bbec2fdf6e45fcb 100755 (executable)
--- a/tools/idf_tools.py
+++ b/tools/idf_tools.py
@@ -442,7 +442,7 @@ class IDFTool(object):
             raise ToolExecError('Command {} has returned non-zero exit code ({})\n'.format(
                 ' '.join(self._current_options.version_cmd), e.returncode))
 
-        in_str = version_cmd_result.decode()
+        in_str = version_cmd_result.decode("utf-8")
         match = re.search(self._current_options.version_regex, in_str)
         if not match:
             return UNKNOWN_VERSION