Created attachment 195712 [details]
Upgrading to FreeBSD 12 silently breaks dsbmd since revision 319735 removed the msdosfs option "large".
I first thought you had not propagated the change to the configuration file, especially because I had the last version of dsbmd before the upgrade and because of the (clever) way you address the issue at build time.
Unfortunately, users who installed and configured dsbmd before upgrading to FreeBSD 12 would face mount errors if they do not update their configuration file.
The attached patch file let you add a pkg-message file to the port so that the users are informed of this problem. Other possible workarounds include forking 1004 into 1204 to trigger your cfgversion mechanism or checking FreeBSD version at run time to conditionally ignore the large option.
(In reply to Samy Mahmoudi from comment #0)
thank you for the report. I decided to let DSBMD ignore the "large" option on FreeBSD >= 12. The change is available in version 1.4: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230559
A commit references this bug:
Date: Sun Aug 12 12:44:33 UTC 2018
New revision: 476988
sysutils/dsbmd: Update to 1.4
Changes since 1.3
- Detach md(4) devices when they are ejected.
- Open listening socket before scanning attached devices, so that clients can
connect even if DSBMD is busy with slow devices.
- Ignore the deprecated "large" mount option for msdosfs on FreeBSD >= 12. This
is necessary for users upgrading their system to FreeBSD 12 without adjusting
dsbmd.conf. Thanks to Samy Mahmoudi for pointing this out. 
- Support for bootable USB drives with ISO-9660 has been added. Thanks to jmp-2
- Support for nvd(4) and uzip memory disks has been added.
PR: 230256 
Submitted by: Marcel Kaiser <firstname.lastname@example.org> (maintainer)
Reported by: Samy Mahmoudi <email@example.com>