The portable build's own SDL was configured without XInput 2.1's scroll
classes: SDL's check links a test program against the system root's
libX11, whose libxcb the system root has not got, so the check failed.
Built that way, SDL still drops the wheel's button events as emulated by
XInput 2 but reads no scroll valuators, so under X11 the wheel sent
nothing. CMake's checks now link with --allow-shlib-undefined, and
tools/linux_sysroot.py requires SDL_VIDEO_DRIVER_X11_XINPUT2_SUPPORTS_SCROLLINFO.
(cherry picked from commit 311f02bb50d4a0d2ffaf372a474ca0e8e98168c6, without
its 64-bit system root, which OpenCE does not have)
The Linux release did not start on a Steam Deck: it was linked against the
build machine's glibc (Arch's, so it asked for GLIBC_2.43; SteamOS 3.8 has
2.41) and needed a 32-bit SDL3, which SteamOS, whose system is read-only,
and most distributions do not have.
The portable build (configure.py --portable, which tools/ci_build.py and so
every GitHub Actions build uses) is now compiled and linked against the
32-bit glibc 2.31 of Debian 11, the Steam Runtime 3 ("sniper") baseline,
and brings its own SDL 3.4.16, libSDL3.so.0 beside the executable, which
finds it there first: a DT_RPATH of $ORIGIN (--disable-new-dtags), which
comes before LD_LIBRARY_PATH, as Steam sets one for the games it starts.
tools/linux_sysroot.py downloads the Debian packages and SDL's source
release into build/linux/third_party, from a ninja edge, so only a Linux
build fetches them. Each package comes from archive.debian.org, else
deb.debian.org, else snapshot.debian.org (a permanent URL, at a time when
the package was in the archive); SDL from its GitHub release, else
libsdl.org. Each URL is tried three times, a moment apart, and each file
checked against its SHA-256. tools/linux_sysroot.cmake builds SDL against
the same system root, with X11, Wayland, libdecor (Debian 12's, for
GNOME's window decorations), PipeWire, PulseAudio, ALSA, udev and D-Bus
loaded when it starts, and the build stops if SDL lacks one of them or
would link to libdecor. A build without --portable is as before. The
workflow installs CMake, pkgconf and wayland-scanner instead of lib32-sdl3,
and caches the downloads; the release zip gains libSDL3.so.0 and its
license (SDL3-LICENSE.txt), and the self-updater deletes their .old copies.
With --pgo=train, the instrumented build's copy of libSDL3.so.0 is made
before it plays.
The release build needs GLIBC_2.29 at most (halo and libSDL3.so.0, by
readelf -V), and links only to libSDL3.so.0, libm, libpthread, libdl,
libgcc_s and libc; libSDL3.so.0 only to libm, libdl, libpthread and libc
(libdecor-0.so.0 is a name it loads, not a dependency). It should start on
Debian 11, Ubuntu 20.04, Fedora 32 and later, untested: there, the 32-bit
Wayland libraries are older than the 1.20 that SDL's Wayland driver needs,
so SDL uses X11 (XWayland in a Wayland session). On a Steam Deck (SteamOS
3.8.16, Game Mode, started as Steam starts a non-Steam game), the upstream
release stops at load time (libSDL3.so.0 not found; GLIBC_2.43 not found);
this one loads b30 on the GPU (radeonsi, OpenGL 4.6) and exits with status
0 at debug.exit_after, with its own libSDL3.so.0 though LD_LIBRARY_PATH
names a folder holding another. Debug and release builds from an empty
build folder (every download), and tools/test_linux_port.py,
tools/harness and tools/test_light_storage.py, pass in an Arch container
with the workflow's packages.
Milenko