-- testing read-write-loop/fd --------------------------------------------
    giving offsets ................................................... [ PASS]
    giving size ...................................................... [ PASS]
    giving size and offset ........................................... [ERROR]
        
Error: (open-input-file) cannot open file - No such file or directory: "/tmp/sendfile-test.data.out"
    (begin
      (with-prepared-environment
        offset-test-file
        (lambda (in out)
          (parameterize
            ((force-implementation 'read-write))
            (sendfile in out offset: 213 bytes: 15)))
        #t)
      (file-contents test-file-out))
    3 tests completed in 0.003 seconds.
    1 error (33.3%).
    2 out of 3 (66.7%) tests passed.
    -- done testing read-write-loop/fd ---------------------------------------