[Bug]: `saltutil.runner` fail with a `getpwnam` `KeyError` when the master process runs as root

What happened?

Rendering SLS:

'...:queued.wrapper' failed: Problem running salt function in Jinja template: Failed to run 'queue.insert' as user 'Reactor': KeyError: "getpwnam(): name not found: 'Reactor'"

Setup

• Salt master running as root (euid 0).
• Salt 3006.27 (onedir).

Steps to reproduce the behaviour:

mkdir -p /etc/salt/master.d /srv/reactor /srv/salt/orch

/etc/salt/master.d/reactor.conf
reactor:
- 'repro/runas':
    - /srv/reactor/orch.sls

/srv/reactor/orch.sls 
run_orch:
runner.state.orchestrate:
  - args:
      - mods: orch.repro

/srv/salt/orch/repro.sls 
{% do salt['saltutil.runner']('test.arg', ['hello']) %}
noop:
  test.nop

systemctl restart salt-master

On minion fire the event:

salt-call event.send 'repro/runas'

Watch the master log. The runner call raises the KeyError shown under Actual behavior.

Type of salt install

Official rpm

Major version

3006.x

What supported OS are you seeing the problem on? Can select multiple. (If bug appears on an unsupported OS, please open a GitHub Discussion instead)

rockylinux-8

salt --versions-report output

Salt Version:
          Salt: 3006.27

Python Version:
        Python: 3.11.15 (main, Jun 29 2026, 22:21:49) [GCC 11.2.0]

Dependency Versions:
          cffi: 2.0.0
      cherrypy: 18.10.0
  cryptography: 47.0.0
      dateutil: 2.8.2
     docker-py: Not Installed
         gitdb: 4.0.12
     gitpython: Not Installed
        Jinja2: 3.1.6
       libgit2: Not Installed
  looseversion: 1.3.0
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.1.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     packaging: 24.0
     pycparser: 3.00
      pycrypto: Not Installed
  pycryptodome: 3.23.0
        pygit2: Not Installed
  python-gnupg: 0.5.6
        PyYAML: 6.0.3
         PyZMQ: 27.1.0
        relenv: 0.22.16
         smmap: 5.0.2
       timelib: 0.3.0
       Tornado: 6.5.5
           ZMQ: 4.3.5

System Versions:
          dist: rocky 8.10 Green Obsidian
        locale: utf-8
       machine: x86_64
       release: 4.18.0-553.141.1.el8_10.0.1.x86_64
        system: Linux
       version: Rocky Linux 8.10 Green Obsidian

Reproduce the failure with a root-running Salt master using the provided reactor, orchestration SLS, and Jinja saltutil.runner call. Trace the queue.insert and runner.state.orchestrate path when invoking test.arg as user 'Reactor'. Done means the reproduced scenario no longer raises the getpwnam KeyError and the behavior is covered by a regression test.