While installing jenkins-2.46.1 I encountered the following error:
 
/var/log/install.log

Apr  1 13:12:44 AMCHOUKI-M-C091 installd[669]: ./postinstall: <dscl_cmd> DS Error: -14009 (eDSUnknownNodeName)

Apr  1 13:12:44 AMCHOUKI-M-C091 installd[669]: ./postinstall: list: Invalid Path

Apr  1 13:12:44 AMCHOUKI-M-C091 installd[669]: ./postinstall: No jenkins user found, creating jenkins user and group

Apr  1 13:12:44 AMCHOUKI-M-C091 installd[669]: ./postinstall: ERROR: All system uids are in use!

Looking at the postinstall script the current code does the following to get a uid bellow 500 for jenkins:

 
uid=$(dscl . -list /Users uid | sort -nrk 2 | awk '$2 < 500 \{print $2 + 1; exit 0;}')

On my OS X system I have the following uids at the beginning of the list:

499
498
252

uid will be 500 after running this command and the postinstall script will fail because of this condition:

 
if [ $uid -eq 500 ];
then
    echo 'ERROR: All system uids are in use!'
    exit 1
fi

From the above uids it is clear that jenkins could use any uids between 252 and 498. A second concern is that the command does not check if $2 + 1 is already in use.

I would like to propose the following change to find a uid for jenkins bellow 500:

    uids=$(dscl . -list /Users uid | sort -nrk 2 | awk '$2 < 500 {print $2;}')
    echo "uids: $uids"
    uid=0
    prev_uid=500
    found_uid=false
    for i in $uids;
    do
        uid=$(($i + 1))
        if [ "$uid" != "$prev" ]
        then
            echo "Found an available uid"
            found_uid=true
            break
        fi
        prev_uid=$i
    done
    if [ "$found_uid" = false ]; then
        echo 'ERROR: All system uids are in use!'
        exit 1
    fi

 
Let me know if that makes sense. I tried to look for the postinstall in the git repo of jenkins but could not find it.