```
rc: Honor ${name}_env when a custom *_cmd is define (e.g., start_cmd)
A user may set ${name}_env variable in rc.conf(5) in order to set additional
environment variables for a service command. Unfortunately, at the moment this
variable is only honored when the command is specified via the command
variable. Those additional environment variables are never set if the service
is started via the ${rc_arg}_cmd variable (for example start_cmd).
PR: 239692
```
- https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=239692