No USB connection - phone not seen!

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Tried installing Phosh via pmbootstrap and finally got a dmesg awknolegment of the phone on usb.

[ 5215.995226] EXT4-fs (sdb2): mounted filesystem with ordered data mode. Opts: (null)
[ 5216.517404] EXT4-fs (sdb1): mounting ext2 file system using the ext4 subsystem
[ 5216.523174] EXT4-fs (sdb1): mounted filesystem without journal. Opts: (null)
[ 5322.801551] EXT4-fs (sdb2): mounted filesystem with ordered data mode. Opts: (null)

[ 3682.708035] usb 1-1.5: new high-speed USB device number 6 using ehci-pci
[ 3682.817674] usb 1-1.5: New USB device found, idVendor=18d1, idProduct=d001, bcdDevice= 5.07
[ 3682.817679] usb 1-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 3682.817682] usb 1-1.5: Product: PINE64 PinePhone
[ 3682.817684] usb 1-1.5: Manufacturer: PINE64
[ 3682.817686] usb 1-1.5: SerialNumber: postmarketOS
[ 3682.922242] usbcore: registered new interface driver cdc_ether
[ 3682.927151] rndis_host 1-1.5:1.0 usb0: register 'rndis_host' at usb-0000:00:1a.0-1.5, RNDIS device, be:9d:4e:c9:90:79
[ 3682.927174] usbcore: registered new interface driver rndis_host
[ 3682.954316] usbcore: registered new interface driver rndis_wlan
[ 3682.958916] rndis_host 1-1.5:1.0 enp0s26u1u5: renamed from usb0
[ 3683.004472] IPv6: ADDRCONF(NETDEV_UP): enp0s26u1u5: link is not ready
[ 3687.094429] usb 1-1.5: USB disconnect, device number 6
[ 3687.096033] rndis_host 1-1.5:1.0 enp0s26u1u5: unregister 'rndis_host' usb-0000:00:1a.0-1.5, RNDIS device

I wonder why usb disconnected?

looks like usb0 was renamed enp0s26u1u5.

Dev name changes happened for more stability in device names.

You could try changing usb0 part in network setup (computer end) to the name enp0s26u1u5.

I was seeing similar style issues when trying to flash multiple OSes to emmc or sdcards using the device. Try a different cord first. I found that the cord that was supplied quickly deteriorated.  This was causing the devname to change constantly on the device. No clue why.  Could watch it using `udevadm monitor`

udevadm monitor unresponsive to the phone diss/connecting. Bizarrely, just after reading your suggestion nmcli showed the phone and I was able to usb/ethernet access it for a moment (first time since July). Rebooted and lost it again - guess I'll get another cable. Thanks @plainenough.