Updating PHD2 on StellarMate OS – and What I Found Out
For a while now, StellarMate OS has been showing me a notification that a new version of PHD2 is available. At some point I actually wanted to take care of it. What I found out was sobering – but at least instructive.
Starting point
Installed: StellarMate OS 1.x (Raspberry Pi, not version 2.0). PHD2 version according to “About PHD2”: 2.6.13dev8.
First attempt: add-apt-repository
I start with the obvious approach – the PHD2 PPA by Patrick Chevalley:
sudo add-apt-repository ppa:pch/phd2Result: Command not found.
Reason: software-properties-common is not installed. After installing the package the command works, but yields nothing useful – because StellarMate OS is not based on Ubuntu, it’s based on Raspberry Pi OS (Debian Bookworm). PPAs are Ubuntu-specific and don’t work reliably on Debian.
Second attempt: apt directly
sudo apt install --only-upgrade phd2Output:
phd2 is already the newest version (2.6.14+20260405095221~stable~bookworm).So the system claims 2.6.14 is already installed. But PHD2 itself reports 2.6.13dev8 both in the terminal and in the GUI. Contradiction.
Root cause analysis
I take a closer look at the actual binary being executed:
which phd2
# → /usr/bin/phd2
ls -la /usr/bin/phd2
# → 105 bytes – that's not a program, that's a shell script
cat /usr/bin/phd2#!/bin/sh
export LD_LIBRARY_PATH="/usr/lib/phd2${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
exec "$0.bin" "$@"/usr/bin/phd2 is just a wrapper. The actual binary is /usr/bin/phd2.bin:
/usr/bin/phd2.bin --version
# → 2.6.13dev8Forced reinstall:
sudo apt install --reinstall phd2The package is unpacked and configured again – version according to dpkg: 2.6.14. Version reported by the binary afterwards: still 2.6.13dev8.
Direct look inside the package
I manually extract the cached .deb package:
dpkg -x /var/cache/apt/archives/phd2_2.6.14+20260405095221~stable~bookworm_arm64.deb /tmp/phd2test
/tmp/phd2test/usr/bin/phd2.bin --version
# → 2.6.13dev8The package labelled 2.6.14 contains a binary that identifies itself as 2.6.13dev8.
Conclusion – and an open question
This is a mistake on StellarMate’s side: the package version was bumped to 2.6.14, but the actual PHD2 binary inside is still the dev8 build of 2.6.13.
What I cannot answer: whether the new features of 2.6.14 – updated camera SDKs for ZWO ASI and Altair, updated INDI client 2.1.6 – are actually built in or not. The binary could internally be newer than the version string suggests, if the --version output simply wasn’t updated. That could only be verified by testing with the relevant hardware directly.
What I can say: the update notification in the StellarMate interface is misleading – there is no further upgrade available to install via apt. Anyone who absolutely wants the real 2.6.14 binary would need to compile PHD2 from source. For normal guiding use, that’s not worth the effort.
Tested on: StellarMate OS 1.8.x, Raspberry Pi 5, Debian Bookworm (arm64)