Unmappable characters in filename break project detection

I'm using a Github Codespace with the default image. It has a UTF-8 locale:

$ locale
LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

In the project there is a file that is using a UTF-8 character in the filename. Until I remove it, the plugin is unable to detect the project. The log file contains the message

java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters: /home/codespace/my-project/target/test-classes/data-files/Grundfl��chen.dat

To me this looks like the filename is UTF-8 (the character is an ä) but the scanner does not treat it as UTF-8 but rather ASCII.

从项目检测和扫描器路径处理开始，在 Codespace 中使用包含 ä 等字符的 UTF-8 文件名重现该问题。跟踪文件名的解码过程，直到出现 InvalidPathException；项目能够成功检测且不删除该文件即表示完成。