I am attempting to connect a mobile phone running Android to my Debian 9 droplet for debugging. My host is a Mac running Mojave 10.14.6, and it has two USB ports.

When I run adb devices, I get an empty list (see this Stack Overflow post for details).
dmesg returns only one USB: usb1 which is the Linux host controller. However, uhci_hcd lists 2 ports as detected, although usb2 is not detected anywhere else.

I haven’t found any similar issues despite much searching. This blog post has a recipe for detecting and mounting a USB hard drive, but I’m not sure that this is the solution I am looking for as fdisk -l does not show the USB device.

Could anyone advise on what my next steps should be?