[noah-peeters]

Fixes #179. It covers both problems reported there.

1. Segfault on Ctrl/Alt on Ubuntu 26.04 (and Fedora 44, Arch)

PyInstaller bundled the build runner's (ubuntu-24.04) GLib, GTK3, X11 and libstdc++ into the AppImage. At runtime the user's own GVfs, GTK and Mesa plugins get loaded into the app. On newer distros those plugins need newer libs than the bundled ones. On Ubuntu 26.04, the first Ctrl press loads GVfs against the bundled GLib 2.80 and crashes with undefined symbol: g_variant_builder_init_static.

• chimpstackr.spec: on Linux, drop those build-host libs from the bundle so the system's copies are used. The list is the bundled libs that the system's GIO/GVfs/GTK/Mesa plugins depend on. Libs that wheels vendor (hashed names) stay bundled. libgthread and libbz2 also stay, because openSUSE and Fedora don't provide them under the same name.
• build.yml: fail the Linux build if GLib, GTK or libstdc++ get bundled again.

2. A local build keeps opening new windows forever (Python 3.14)

On Python 3.14 the default multiprocessing start method on Linux is forkserver. Because of that, numba's parallel-backend lock makes multiprocessing start its resource tracker by running sys.executable. In a frozen app that executable is ChimpStackr itself, so a second app started, then a third, and so on. CI builds use Python 3.11 (start method fork), so release builds weren't affected, but builds made with scripts/build_linux.sh on 26.04 were.

• src/run.py, src/cli.py: call multiprocessing.freeze_support() first thing.

Testing

Run in amd64 Docker containers on Xvfb. The app was started, sent Ctrl, Ctrl, Ctrl+Z, Ctrl+Y and Ctrl+O (file dialog), then Escape. There was also a CLI --align stack of tests/low_res_images and an ldd check of every bundled .so.

Distro	v0.3.5	This PR (CI artifact)
Ubuntu 26.04 (Xfce, as reported)	segfault on first Ctrl	OK. System GLib 2.88, GTK and GVfs load
Ubuntu 24.04	OK	OK
Debian 13	survives, but GVfs fails to load (undefined symbol)	OK, GVfs loads
Fedora 44	segfault on first Ctrl	OK*
Arch	segfault on first Ctrl	OK*
openSUSE Tumbleweed	—	OK

* Under heavy parallel load in Docker, GTK's glycin image loader sometimes picks its bwrap sandbox, which can't run in an unprivileged container, and GTK then aborts on the file dialog icon. With GLYCIN_DISABLE_SANDBOX=1 it passes every time. On a real desktop bwrap works, so this is expected to be a container artifact. It hasn't been tested on real Fedora or Arch hardware.

For the spawn bug, I built master and this branch with Python 3.14.4 and PyInstaller 6.22.3 on Ubuntu 26.04, the same way build_linux.sh does:

• master: 27 processes and 78 windows after 75 s, still growing.
• This branch: 1 app plus 1 resource tracker, steady. The tracker exits with the app.

Unit tests: 92 passed.

Not covered: real hardware, Wayland sessions.

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