it seems it is a feature of android 6, it has the ability to treat an external sdcard as internal memory http://androidcommunity.com/android-...rage-20151021/
if you choose to use it as internal memory it gets reformatted and encrypted. I don't think this is a good idea for us since it might reformat the whole card and not just the FAT32
If I give root access to file manager, I can see /sdcard but it looks to be symlinked with /storage/emulated/0 because i can't see existing files on my FAT32. So the FAT32 is not mounted. i have the notification that it is corrupted, and in settings/Storage & USB the Portable Storage SD Card is described as corrupted. It might be because it is partitioned.
I will try another sdcard and see what happens.
Edit; I have attached a dmesg of this first install.
Edit2; i re-installed on a fresh sdcard and after booting i tapped on the "fix it" notification to format, a progress bar got about a third of the way then there was an error which flashed on the screen briefly, but the rom seemed to still work ok. I then switched off the rom. But it wont boot again now, hangs on htc screen. from dmesg it can't mount sdext or sdext2 (attached dmesg2.txt).
i still have the sdrecovery on the sdcard, so it didn't format the FAT32, seems to have just wiped or formatted the 2 ext partitions. in recovery, i can't mount either partition.
So don't try to "fix" the sdcard.
Edit3; looking at the sdcard from minitool, there is only 1 partition. it seems to have deleted sdext and sdext2 (i also had a swap partition at the end which has also gone). So there is now unused space on the sdcard.
I wonder if you get the notification if using ext4 partitions, probably.
Edit4; ok, have re-installed with 2 ext4 partitions and still get the notification. I have the feeling that ext4 is a tad more responsive than f2fs, anyone else?
I have adb working over windows. after plugging in usb I got a notification "usb for charging" clicking this gave me the option to use mtp for file transfers. This option makes the phone discoverable via adb. hooray.
Edit5; mount does not show mmcblk0p1 perhaps it needs to be done in fstab? Attached screenshot
Edit6; I see camera and sim toolkit in settings/apps, but I don't see them in the apps drawer. So cant use them
play store force closes.