snap mosquitto_passwd Error: Unable to open temporary file. No such file or directory

[anq4]

Hello.

Using latest snap mosquitto 2.0.21

trying to add a user gives an error

[root@wis1 conf.d]# mosquitto_passwd /var/snap/mosquitto/common/conf.d/wis2.passwd testuser
Error: Unable to open temporary file. No such file or directory.

backup password file is done but command doesn't even ask for password and user is not added

[root@wis1 conf.d]# ll
total 20
-rw-r--r-- 1 root root 213 May 2 10:10 wis2.conf
-rwx------ 1 root root 468 Apr 17 18:49 wis2.passwd
-rwx------ 1 root root 468 Apr 17 18:49 wis2.passwd.2025-05-14
-rw------- 1 root root 468 May 14 18:17 wis2.passwd.backup.1BxV1V
-rw------- 1 root root 468 May 14 18:14 wis2.passwd.backup.9CufH5

[anq4]

Previous mosquitto 2.0.1x versions did work just fine on the same RHEL8 system

[anq4]

Revision in use is 978

mosquitto 2.0.21 978 latest/stable mosquitto✓ -

[anq4]

[root@wis1 ~]# snap info mosquitto
name: mosquitto
summary: Eclipse Mosquitto MQTT broker
publisher: Mosquitto Team (mosquitto✓)
store-url: https://snapcraft.io/mosquitto
contact: https://mosquitto.org/
license: unset
description: |
This is a message broker that supports version 5.0, 3.1.1, and 3.1 of the MQTT protocol. MQTT
provides a method of carrying out messaging using a publish/subscribe model. It is lightweight,
both in terms of bandwidth usage and ease of implementation. This makes it particularly useful at
the edge of the network where a sensor or other simple device may be implemented using a
microcontroller for example.
commands:

• mosquitto.ctrl
• mosquitto.passwd
• mosquitto.pub
• mosquitto.rr
• mosquitto.sub
  services:
  mosquitto: simple, enabled, active
  snap-id: mDxT0cGOHKSs62MOHSK5Ype0Na5UU2LB
  tracking: latest/stable
  refresh-date: 18 days ago, at 22:33 UTC
  channels:
  latest/stable: 2.0.21 2025-05-01 (978) 3MB -
  latest/candidate: ↑
  latest/beta: ↑
  latest/edge: 2.0.21 2025-05-01 (978) 3MB -
  1.6/stable: 1.6.15 2022-03-17 (702) 835kB -
  1.6/candidate: ↑
  1.6/beta: ↑
  1.6/edge: 1.6.15 2022-07-08 (747) 831kB -
  installed: 2.0.21 (978) 3MB -

[Paraphraser]

Not sure what "snap" is (please pardon my ignorance) but see if this helps because it sounds like the same problem. You likely need the -c to create the file and -b so passwords can be passed on the command line.