man -f/-k [keyword]在fedora 29 中报错nothing appropriate

[root@localhost tmp]# man -k aio
aio (7)       - POSIX asynchronous I/O overview
aio.h (0p)      - asynchronous input and output
aio_cancel (3)    - cancel an outstanding asynchronous I/O request
aio_cancel (3p)   - cancel an asynchronous I/O request
aio_error (3)    - get error status of asynchronous I/O operation
aio_error (3p)    - retrieve errors status for an asynchronous I/O operation
aio_fsync (3)    - asynchronous file synchronization
aio_fsync (3p)    - asynchronous file synchronization
aio_init (3)     - asynchronous I/O initialization
aio_read (3)     - asynchronous read
aio_read (3p)    - asynchronous read from a file
aio_return (3)    - get return status of asynchronous I/O operation
aio_return (3p)   - retrieve return status of an asynchronous I/O operation
aio_suspend (3)   - wait for asynchronous I/O operation or timeout
aio_suspend (3p)   - wait for an asynchronous I/O request
aio_write (3)    - asynchronous write
aio_write (3p)    - asynchronous write to a file