update(flatpak): default local builds to 2 jobs

CHANGELOG.md

@@ -45,6 +45,13 @@ GitHub are taken from the matching section here.
   `MOCKTAIL_LOCAL_STORAGE_CURRENT_USER_ID` is now ignored instead of being
   partly read.
 
+### Changed
+
+- `make flatpak` and `scripts/build_flatpak.sh` now build with 2 jobs by
+  default instead of 4, so a local Flatpak build is less likely to run out
+  of memory. Set `FLATPAK_JOBS` or `MOCKTAIL_FLATPAK_JOBS` to use more.
+  Thanks to @glook9001.
+
 ## [0.3.1] - 2026-09-20
 
 ### Added

Makefile

@@ -21,7 +21,7 @@ ANYLINUX_APPIMAGETOOL ?= appimagetool
 PREFIX ?= /usr
 FLATPAK_BUILD_DIR ?= build-flatpak
 FLATPAK_MANIFEST ?= packaging/flatpak/io.github.CoderDayton.nightcap.json
-FLATPAK_JOBS ?= 4
+FLATPAK_JOBS ?= 2
 
 define build_native_runtime
 	@git submodule update --init --recursive

scripts/build_flatpak.sh

@@ -10,7 +10,7 @@ readonly PROJECT_ROOT="$(cd -- "${SCRIPT_DIR}/.." && pwd -P)"
 
 BUILD_DIR="${PROJECT_ROOT}/build-flatpak"
 MANIFEST="${PROJECT_ROOT}/packaging/flatpak/io.github.CoderDayton.nightcap.json"
-JOBS="${MOCKTAIL_FLATPAK_JOBS:-4}"
+JOBS="${MOCKTAIL_FLATPAK_JOBS:-2}"
 
 Usage() {
   cat <<'EOF'
@@ -21,7 +21,7 @@ Build and install Mocktail as a per-user Flatpak for the host architecture.
 Options:
   --build-dir DIR  Builder output directory (default: build-flatpak).
   --manifest FILE  Flatpak manifest path.
-  --jobs N         Maximum parallel build jobs (default: 4).
+  --jobs N         Maximum parallel build jobs (default: 2).
   -h, --help       Show this help.
 EOF
 }

tests/flatpak_packaging_test.sh

@@ -176,8 +176,10 @@ grep -Fq './scripts/build_flatpak.sh' <<<"${dry_run}" ||
   Fail 'make flatpak does not invoke the guarded Flatpak builder'
 grep -Fq -- '--manifest packaging/flatpak/io.github.CoderDayton.nightcap.json' \
   <<<"${dry_run}" || Fail 'make flatpak lost the canonical manifest'
-grep -Fq -- '--jobs 4' <<<"${dry_run}" ||
+grep -Fq -- '--jobs 2' <<<"${dry_run}" ||
   Fail 'make flatpak does not cap local build parallelism'
+grep -Fq 'JOBS="${MOCKTAIL_FLATPAK_JOBS:-2}"' "${BUILD_HELPER}" ||
+  Fail 'Flatpak helper does not cap local build parallelism'
 
 mkdir -p -- "${TEMP_DIR}/bin"
 cat >"${TEMP_DIR}/bin/uname" <<'EOF'