pixelpass/packaging/debian

Debian / Ubuntu .deb build

This documents how the pixelpass_*.deb is produced. The deb recipe itself lives in-repo as the [package.metadata.deb] block in Cargo.toml (cargo-deb's equivalent of a PKGBUILD); this file documents only the build environment.

pixelpass is the screen-share companion to peerspeak and is built the same way in the same box. See peerspeak's packaging/debian/README.md for the full rationale behind each step — this is the short version.

TL;DR

distrobox enter peerspeak-bookworm -- bash -lc '
  source ~/.cargo/env
  cd ~/git/butter/pixelpass
  export CARGO_TARGET_DIR=~/.cache/cargo-deb-targets/pixelpass   # MANDATORY
  cargo deb
'
# output: $CARGO_TARGET_DIR/debian/pixelpass_<version>-1_amd64.deb

Build environment

• Base: the same Debian 12 (bookworm) distrobox peerspeak-bookworm (glibc 2.36) used for peerspeak. Never build on the Arch host (newer glibc
  • shared $HOME/target/ would link Arch C objects into the binary).
• Use a box-local, pixelpass-specific CARGO_TARGET_DIR (distinct from peerspeak's) so the two never share an artifact cache: export CARGO_TARGET_DIR=~/.cache/cargo-deb-targets/pixelpass.
• Toolchain provisioning (rustup stable + cargo-deb + build-essential pkg-config) is identical to peerspeak's README. pixelpass itself links few C libraries — the heavy GStreamer stack it uses is invoked as subprocesses, not linked (see below), so it adds no extra *-dev build-deps beyond the base.

Why Depends lists the whole GStreamer stack explicitly

pixelpass does its screen capture by shelling out to the GStreamer CLI (gst-launch-1.0 / gst-inspect-1.0) and to pactl, not by linking the GStreamer libraries. That means dpkg-shlibdeps (which only sees linked .so files) cannot detect them, so $auto alone would ship a .deb whose Depends omits the entire capture stack. A fresh Ubuntu host would then fail at pixelpass's own deps::check_host_binaries startup probe — before it ever prints a connection ticket, which is exactly the field bug that motivated this.

So the Cargo.toml depends hard-codes the runtime stack on top of $auto:

$auto, gstreamer1.0-tools, gstreamer1.0-plugins-base,
gstreamer1.0-plugins-good, gstreamer1.0-plugins-bad,
gstreamer1.0-plugins-ugly, gstreamer1.0-libav, gstreamer1.0-pipewire,
gstreamer1.0-pulseaudio, pulseaudio-utils, x11-utils

This covers both capture backends (pipewiresrc on Wayland, ximagesrc on X11 from plugins-good), the VAAPI + software H.264 encoders, the AAC/TS mux tail, the PulseAudio source, and the pactl/xdpyinfo helpers.

glibc floor

Same as peerspeak: built against glibc 2.36 → runs on Debian 12+ / Ubuntu 24.04+. (pixelpass's own linked-library floor is lower, ~2.39-era, but it is always shipped alongside peerspeak, whose 2.36 floor governs the pair.)