`pm2 startup` does not take environment variable `PM2_HOME` into account

What's going wrong?

When I set PM2_HOME environment variable, the systemd unit file generated by pm2 startup is expected to use the value of PM2_HOME. But it still generates the following without considering my custom value of PM2_HOME

Environment=PM2_HOME=<my home>/.pm2
PIDFile=<my home>/.pm2/pm2.pid

How could we reproduce this issue?

export PM2_HOME="/some/new/path"
pm2 startup # Add --preserve-env='PM2_HOME' to generated sudo command
systemctl cat pm2-$(id -nu).service

Supporting information

--- PM2 report ----------------------------------------------------------------
Date                 : Thu Jun 20 2024 22:02:07 GMT+0800 (China Standard Time)
===============================================================================
--- Daemon -------------------------------------------------
pm2d version         : 5.4.0
node version         : 22.3.0
node path            : /fhome/fuxd/.nvm/versions/node/v22.3.0/bin/pm2
argv                 : /fhome/fuxd/.nvm/versions/node/v22.3.0/bin/node,/fhome/fuxd/.nvm/versions/node/v22.3.0/lib/node_modules/pm2/lib/Daemon.js
argv0                : node
user                 : fuxd
uid                  : 2002
gid                  : 2002
uptime               : 14min
===============================================================================
--- CLI ----------------------------------------------------
local pm2            : 5.4.0
node version         : 22.3.0
node path            : /fhome/fuxd/.nvm/versions/node/v22.3.0/bin/pm2
argv                 : /fhome/fuxd/.nvm/versions/node/v22.3.0/bin/node,/fhome/fuxd/.nvm/versions/node/v22.3.0/bin/pm2,report
argv0                : node
user                 : fuxd
uid                  : 2002
gid                  : 2002
===============================================================================
--- System info --------------------------------------------
arch                 : x64
platform             : linux
type                 : Linux
cpus                 : Intel(R) Xeon(R) Gold 5218R CPU @ 2.10GHz
cpus nb              : 80
freemem              : 1029278760960
totalmem             : 1081532235776
home                 : /fhome/fuxd
===============================================================================
--- PM2 list -----------------------------------------------
┌────┬───────────────────┬─────────────┬─────────┬─────────┬──────────┬────────┬──────┬───────────┬──────────┬──────────┬──────────┬──────────┐
│ id │ name              │ namespace   │ version │ mode    │ pid      │ uptime │ ↺    │ status    │ cpu      │ mem      │ user     │ watching │
├────┼───────────────────┼─────────────┼─────────┼─────────┼──────────┼────────┼──────┼───────────┼──────────┼──────────┼──────────┼──────────┤
│ 0  │ data360-check2    │ default     │ N/A     │ fork    │ 2301770  │ 14m    │ 0    │ online    │ 0%       │ 3.3mb    │ fuxd     │ disabled │
└────┴───────────────────┴─────────────┴─────────┴─────────┴──────────┴────────┴──────┴───────────┴──────────┴──────────┴──────────┴──────────┘
===============================================================================
--- Daemon logs --------------------------------------------
/fhome/fuxd/.pm2/sy03/pm2.log last 20 lines:
PM2        | 2024-06-20T21:47:50: PM2 log: ===============================================================================
PM2        | 2024-06-20T21:47:50: PM2 log: --- New PM2 Daemon started ----------------------------------------------------
PM2        | 2024-06-20T21:47:50: PM2 log: Time                 : Thu Jun 20 2024 21:47:50 GMT+0800 (China Standard Time)
PM2        | 2024-06-20T21:47:50: PM2 log: PM2 version          : 5.4.0
PM2        | 2024-06-20T21:47:50: PM2 log: Node.js version      : 22.3.0
PM2        | 2024-06-20T21:47:50: PM2 log: Current arch         : x64
PM2        | 2024-06-20T21:47:50: PM2 log: PM2 home             : /fhome/fuxd/.pm2/sy03
PM2        | 2024-06-20T21:47:50: PM2 log: PM2 PID file         : /fhome/fuxd/.pm2/sy03/pm2.pid
PM2        | 2024-06-20T21:47:50: PM2 log: RPC socket file      : /fhome/fuxd/.pm2/sy03/rpc.sock
PM2        | 2024-06-20T21:47:50: PM2 log: BUS socket file      : /fhome/fuxd/.pm2/sy03/pub.sock
PM2        | 2024-06-20T21:47:50: PM2 log: Application log path : /fhome/fuxd/.pm2/sy03/logs
PM2        | 2024-06-20T21:47:50: PM2 log: Worker Interval      : 30000
PM2        | 2024-06-20T21:47:50: PM2 log: Process dump file    : /fhome/fuxd/.pm2/sy03/dump.pm2
PM2        | 2024-06-20T21:47:50: PM2 log: Concurrent actions   : 2
PM2        | 2024-06-20T21:47:50: PM2 log: SIGTERM timeout      : 1600
PM2        | 2024-06-20T21:47:50: PM2 log: ===============================================================================
PM2        | 2024-06-20T21:48:04: PM2 log: App [data360-check2:0] starting in -fork mode-
PM2        | 2024-06-20T21:48:04: PM2 log: App [data360-check2:0] online

Start at the pm2 startup command and inspect the generated systemd unit with systemctl cat after setting PM2_HOME and using the documented --preserve-env option. Done means the generated Environment and PIDFile entries use the configured PM2_HOME path rather than the default path.