The issue is present, when `Language Settings -> Administrative language settings -> Change system locale... -> Beta: Use Unicode UTF-8 for worldwide language support` is enabled. When option is disabled it works as expected. Please, find below steps to reproduce, cmake and system info. ``` c:\work\test_cmake_tar>cmake -E tar c out.tar -- file.txt CMake Error: archive_write_header: Can't record entry in tar file without pathname CMake Error: Problem creating tar: out.tar c:\work\test_cmake_tar>type file.txt Hi to builtin tar archiver c:\work\test_cmake_tar>cmake --version cmake version 3.16.3 CMake suite maintained and supported by Kitware (kitware.com/cmake). ``` Excerpt from systeminfo output: ``` OS Name: Microsoft Windows 10 Pro OS Version: 10.0.18363 N/A Build 18363 OS Manufacturer: Microsoft Corporation OS Configuration: Standalone Workstation OS Build Type: Multiprocessor Free System Type: x64-based PC System Locale: en-us;English (United States) Input Locale: en-us;English (United States) Time Zone: (UTC+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, ``` This issue may be related to [#20050](https://gitlab.kitware.com/cmake/cmake/issues/20050)