install/60566: Random data file can't be read from mounted device to bootstrap pRNG in the installer due to assumptions about mount status.

["jackemled+netbsd%gmail.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60566
>Category:       install
>Synopsis:       Random data file can't be read from mounted device to bootstrap pRNG in the installer due to assumptions about mount status.
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Aug 09 23:45:00 +0000 2026
>Originator:     jackemled
>Release:        11.0
>Organization:
>Environment:
NetBSD  11.0 NetBSD 11.0 (GENERIC) #0: Thu Jul 30 15:23:12 UTC 2026  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/i386/compile/GENERIC i386
>Description:
Towards the end of the install, once NetBSD has been written to the target storage. The NetBSD installer tests for a cryptographically strong pRNG for use with the system. It correctly detects that this old laptop does not have one, because it is old, and offers several options to provide the system with entropy. I have selected c: Load raw binary random data and chosen to load from a local file system. The installer is unable to mount FAT32 or ext2, so I have chrooted into the newly installed system and manually mounted it at /targetroot/mnt/, then exited the shell and returned to the installer. Upon trying again and providing the file path, the installer still attempts to mount the device despite it already being mounted at the provided path, then because the mount fails it does not progress to reading the file.

I've had to do it this way because I have no way to make a filesystem that the installer understands and I can't host a server on the network for the installer to read the file off of. My only option is to use the installed system through chroot to mount an ext2 or FAT32 partition.
>How-To-Repeat:
1. Install NetBSD on a system with no pRNG hardware, do not exit the installer.
2. You should see a dialogue beginning with "This system send to lack a cryptographically strong pseudo random number generator.", select "c: Load raw binary random data"
3. Press ^z to enter the shell.
4. Plug in a flash drive containing your random data, note what device file it is assigned, in my case /dev/sd1.
5. chroot /targetroot
6. mount -t [Filesystem] /dev/[Your Flash Drive] /mnt
7. ^d^d, then you should be back at the menu where you select where to get your raw random data.
8. Select "d: Load from a local fole system (e.g. a USB device)
9.
     a: Device               [Your Interal Storage]
     b: File System          [Filesystem]
     c: Path and filename    /targetroot/mnt/[File]
     d: Cancel
     x: Load random data

   Pick x once you've entered your options.
10. See the following dialogue at the top of the screen. 
     Status: Command failed
    Command: mount -t [Filesystem] /dev/[Your Internal Storage] /tmp/ent-mnt.######
     Hit enter to continue
11. Press the enter key and be taken back to the menu from step 1.
>Fix:
Check that the device is already mounted, then check if the provided path and file are readable BEFORE actually attempting to mount. If they are, skip mounting, if not, then try to mount, then try to read.

Right now the installer assumes that the device is not mounted, even when it is. When the device is already mounted, attempting to mount it again will fail, then it will not proceed to reading the file.