Can't read files using `fs::read` and `fs::read_to_string`

I tried reading files using the fs helper functions `read` and `read_to_string`. I was lazy to verify the actual return value, but the length of the returned data was considerably shorter (< 4 bytes) than the contents of the files.

Reading the files using `File::open().read()` worked as expected. Writing the files using either `io::Write` or `std::fs::write` works.