build_all: --ram mode (build scratch on tmpfs) for slow storage

Redirect the per-channel build scratch to /dev/shm and skip UPX, a big win when
building from a USB stick / SD card (I/O-bound on flash):
- TMPDIR + PIP_CACHE_DIR -> tmpfs
- PyInstaller: --workpath -> tmpfs (PYI_WORKPATH); UPX off via TESTIUM_NO_UPX
- Flatpak: build dir + ostree repo -> tmpfs (FLATPAK_BUILDDIR/REPODIR); the
  .flatpak-builder download cache stays on disk
- AppImage: bind-mount a tmpfs dir at the in-container AppDir path
  (APPIMAGE_APPDIR_TMPFS)
Scratch is freed on exit. Each build.sh honors the env vars with on-disk
defaults, so behavior is unchanged without --ram. With --ram, prefer --serial
on RAM-limited machines (flatpak+appimage are ~1 GB each).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

build_all.sh

@@ -20,6 +20,11 @@
 # of the parallel phase is captured under dist/.build-logs/<step>.log and the
 # log of any failing step is printed at the end.
 #
+# Pass --ram to redirect the per-channel build scratch (PyInstaller workpath,
+# Flatpak build dir + ostree repo, AppImage AppDir) and TMPDIR/PIP_CACHE_DIR to
+# /dev/shm, and skip UPX. Big speedup on slow/flash storage. On a RAM-limited
+# machine combine with --serial (e.g. ./build_all.sh --ram --serial).
+#
 # All artifacts are collected (copied) under <repo>/dist/. Original outputs in
 # src/dist/, package/*/dist/, doc/manual/ are left in place. Wheel and AppImage
 # keep their original names (which already contain the version); manual,
@@ -36,10 +41,12 @@ set -e
 
 CLEAN=0
 SERIAL=0
+RAM=0
 for arg in "$@"; do
     case "$arg" in
         --clean|-c) CLEAN=1 ;;
         --serial)   SERIAL=1 ;;
+        --ram)      RAM=1 ;;
         *) echo "Unknown option: $arg" >&2; exit 1 ;;
     esac
 done
@@ -74,6 +81,30 @@ export REQ_PATH="$SCRIPT_DIR/src/requirements.txt"
 bash "$SCRIPT_DIR/scripts/build_env.sh"
 source "$SCRIPT_DIR/scripts/set_env.sh"
 
+# ---------- RAM mode: put build scratch on tmpfs (--ram) ----------------------
+# On slow storage (USB stick, SD card) the per-channel build dirs and temp
+# churn dominate. --ram redirects them to /dev/shm and skips UPX. The
+# .flatpak-builder cache stays on disk so source downloads persist. The tmpfs
+# scratch is freed on exit.
+if [ "$RAM" -eq 1 ]; then
+    RAMROOT="/dev/shm/testium-build-${VERSION}"
+    echo "-- RAM mode: build scratch under $RAMROOT (tmpfs), freed on exit"
+    rm -rf "$RAMROOT"
+    mkdir -p "$RAMROOT"/{tmp,pip,pyi-work,flatpak-build,flatpak-repo,appdir}
+    export TMPDIR="$RAMROOT/tmp"
+    export PIP_CACHE_DIR="$RAMROOT/pip"
+    export PYI_WORKPATH="$RAMROOT/pyi-work"           # pyinstaller --workpath
+    export FLATPAK_BUILDDIR="$RAMROOT/flatpak-build"  # flatpak-builder build dir
+    export FLATPAK_REPODIR="$RAMROOT/flatpak-repo"    # ostree repo
+    export APPIMAGE_APPDIR_TMPFS="$RAMROOT/appdir"    # AppDir bind-mount
+    export TESTIUM_NO_UPX=1                           # skip slow UPX in the spec
+    trap 'rm -rf "$RAMROOT"' EXIT
+    if [ "$SERIAL" -ne 1 ]; then
+        echo "   note: with --ram, prefer adding --serial so each step gets the"
+        echo "         full tmpfs and you don't risk OOM (flatpak+appimage are ~1 GB each)."
+    fi
+fi
+
 step() {
     echo
     echo "================================================================"

package/appimage/build.sh

@@ -17,11 +17,20 @@ else
 fi
 echo "Using $RUNTIME — building testium $APP_VERSION AppImage..."
 
+# APPIMAGE_APPDIR_TMPFS (set by build_all --ram) bind-mounts a host tmpfs dir at
+# the AppDir build path, keeping the ~1 GB AppDir churn off slow storage.
+APPDIR_MOUNT=""
+if [ -n "$APPIMAGE_APPDIR_TMPFS" ]; then
+    mkdir -p "$APPIMAGE_APPDIR_TMPFS"
+    APPDIR_MOUNT="-v $APPIMAGE_APPDIR_TMPFS:/work/package/appimage/AppDir"
+fi
+
 # APPIMAGE_EXTRACT_AND_RUN=1 lets appimagetool run without FUSE in the container.
 $RUNTIME run --rm \
     --privileged \
     -e APPIMAGE_EXTRACT_AND_RUN=1 \
     -v "$REPO_ROOT:/work" \
+    $APPDIR_MOUNT \
     -w /work/package/appimage \
     debian:bookworm bash -c "
         set -e

package/flatpak/build.sh

@@ -7,11 +7,15 @@
 
 set -e
 
-# Build + install local
-flatpak-builder --user --verbose --force-clean --install --repo=repo build org.testium.Testium.yaml
+# Build + install local. FLATPAK_BUILDDIR / FLATPAK_REPODIR (set by build_all
+# --ram) redirect the build dir and the ostree repo to tmpfs. The
+# .flatpak-builder cache stays local so source downloads persist between runs.
+BUILDDIR="${FLATPAK_BUILDDIR:-build}"
+REPODIR="${FLATPAK_REPODIR:-repo}"
+flatpak-builder --user --verbose --force-clean --install --repo="$REPODIR" "$BUILDDIR" org.testium.Testium.yaml
 
 # Génère le bundle distribuable
-flatpak build-bundle repo testium.flatpak org.testium.Testium
+flatpak build-bundle "$REPODIR" testium.flatpak org.testium.Testium
 echo "Bundle généré : $(pwd)/testium.flatpak"
 
 # Crée ~/.local/bin/testium pour pouvoir taper "testium" en console

package/pyinstaller/build.sh

@@ -2,11 +2,15 @@
 
 SCRIPT_DIR=$(realpath $( dirname "$0"))
 
-rm -r "${SCRIPT_DIR}/build" "${SCRIPT_DIR}/dist"
+rm -rf "${SCRIPT_DIR}/build" "${SCRIPT_DIR}/dist"
 
 pwd=$(pwd)
 cd ${SCRIPT_DIR}
-pyinstaller testium.spec
+# PYI_WORKPATH (set by build_all --ram) puts the big intermediate build tree on
+# tmpfs; dist/ stays local so build_all can collect the binary.
+WORKARG=""
+[ -n "$PYI_WORKPATH" ] && WORKARG="--workpath $PYI_WORKPATH"
+pyinstaller $WORKARG testium.spec
 RESULT=$?
 if [ -n "$1" ] && [ "$1" = "install" ]; then
     if [ $RESULT -eq 0 ]; then

package/pyinstaller/testium.spec

@@ -89,7 +89,9 @@ exe = EXE(
     debug=False,
     bootloader_ignore_signals=False,
     strip=False,
-    upx=True,
+    # UPX is CPU+IO heavy for a marginal size gain — build_all --ram sets
+    # TESTIUM_NO_UPX=1 to skip it (much faster on slow/flash storage).
+    upx=not os.environ.get("TESTIUM_NO_UPX"),
     upx_exclude=[],
     runtime_tmpdir=None,
     console=True,