id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host
17866,Serial Port/UART cannot be used,GhostGambler,,"I want to use the UART functionality to communicate with the VM (in this example Linux) from macOS.

As configuration I used `--uart2 0x2f8 3` and `--uartmode2 file /tmp/serial_port2`.

The Linux guest says everything is fine:
{{{
$ dmesg | grep tty
[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.15.0-23-generic root=LABEL=cloudimg-rootfs ro console=tty1 console=ttyS0
[    0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.15.0-23-generic root=LABEL=cloudimg-rootfs ro console=tty1 console=ttyS0
[    0.004000] console [tty1] enabled
[    0.004000] console [ttyS0] enabled
[    1.535605] 00:02: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    1.721594] 00:03: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
}}}

The file `/tmp/serial_port2` is created on the macOS file system, but when I want to access it with cat or screen, nothing happens. The commands just exit immediately:
{{{
$ screen /tmp/serial_port2 115200
[screen is terminating]
$ cat serial_port2 
$ 
}}}
If I run the command as root, screen starts and shows the message
{{{
Cannot exec 'serial_port2': No such file or directory  
}}}

If I instead use `--uartmode2 tcpserver 8081`, I can use `nc 127.0.0.1 8081` and I receive data from the VM as expected.

I also created another VM with uartmode=client, but they also cannot communicate with each other.

Is this function not working, or am I doing something wrong?",defect,closed,uart,VirtualBox 5.2.14,invalid,,,Linux,Mac OS X