diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 40c0be1c2cfb..0b70acdb72d0 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -197,7 +197,9 @@ jobs:
       # Generate / upload artifact. {{{
 
       - name: Generate artifact
-        run: make update --assume-old=base
+        # Note: ensure the build skeleton is created, so there are no dangling
+        # symlinks (e.g. `data/dict`) to trip 7zip during artifact generation…
+        run: make skeleton update --assume-old=base
 
       - name: Upload artifact
         uses: actions/upload-artifact@v4
diff --git a/Makefile b/Makefile
index fad49a6170a8..54e609f21cd0 100644
--- a/Makefile
+++ b/Makefile
@@ -14,10 +14,6 @@ ifneq (,$(findstring -,$(VERSION)))
 	VERSION := $(VERSION)_$(RELEASE_DATE)
 endif
 
-# releases do not contain tests and misc data
-IS_RELEASE := $(if $(or $(EMULATE_READER),$(WIN32)),,1)
-IS_RELEASE := $(if $(or $(IS_RELEASE),$(APPIMAGE),$(LINUX),$(MACOS)),1,)
-
 LINUX_ARCH?=native
 ifeq ($(LINUX_ARCH), native)
 	LINUX_ARCH_NAME:=$(shell uname -m)
@@ -50,11 +46,14 @@ WIN32_DIR=$(PLATFORM_DIR)/win32
 
 define CR3GUI_DATADIR_EXCLUDES
 %/KoboUSBMS.tar.gz
+%/NOTES.txt
 %/cr3.ini
 %/cr3skin-format.txt
 %/desktop
 %/devices
+%/dict
 %/manual
+%/tessdata
 endef
 CR3GUI_DATADIR_FILES = $(filter-out $(CR3GUI_DATADIR_EXCLUDES),$(wildcard $(CR3GUI_DATADIR)/*))
 
@@ -71,18 +70,78 @@ INSTALL_FILES=reader.lua setupkoenv.lua frontend resources defaults.lua datastor
 OUTPUT_DIR_ARTIFACTS = $(abspath $(OUTPUT_DIR))/!(cache|cmake|data|history|staging|thirdparty)
 OUTPUT_DIR_DATAFILES = $(OUTPUT_DIR)/data/*
 
+# Release excludes. {{{
+
+define UPDATE_PATH_EXCLUDES
+cache
+clipboard
+data/dict
+data/tessdata
+ev_replay.py
+help
+history
+l10n/templates
+ota
+resources/fonts*
+resources/icons/src*
+screenshots
+spec
+endef
+
+# Files created after execution.
+define UPDATE_PATH_EXCLUDES +=
+data/cr3.ini
+defaults.*.lua
+history.lua
+scripts
+settings
+settings.reader.lua*
+styletweaks
+version.log
+endef
+
+# Testsuite leftovers.
+define UPDATE_PATH_EXCLUDES +=
+dummy-test-file*
+file.sdr*
+readerbookmark.*
+readerhighlight.*
+testdata
+this-is-not-a-valid-file*
+endef
+
+# Globally excluded.
+define UPDATE_GLOBAL_EXCLUDES
+*.orig
+*.swo
+*.swp
+*.un~
+.*
+endef
+
+release_excludes = $(strip $(UPDATE_PATH_EXCLUDES:%='-x!$1%') $(UPDATE_GLOBAL_EXCLUDES:%='-xr!%'))
+
+# }}}
+
+define mkupdate
+cd $(INSTALL_DIR) &&
+'$(abspath tools/mkrelease.sh)'
+$(if $(PARALLEL_JOBS),--jobs $(PARALLEL_JOBS))
+--manifest=$(or $2,koreader)/ota/package.index
+$(foreach a,$1,'$(if $(filter --%,$a),$a,$(abspath $a))') $(or $2,koreader)
+$(call release_excludes,$(or $2,koreader)/)
+endef
+
 all: base
 	install -d $(INSTALL_DIR)/koreader
 	rm -f $(INSTALL_DIR)/koreader/git-rev; echo "$(VERSION)" > $(INSTALL_DIR)/koreader/git-rev
 ifdef ANDROID
 	rm -f android-fdroid-version; echo -e "$(ANDROID_NAME)\n$(ANDROID_VERSION)" > koreader-android-fdroid-latest
 endif
-ifeq (,$(IS_RELEASE))
 	$(SYMLINK) $(KOR_BASE)/ev_replay.py $(INSTALL_DIR)/koreader/
-endif
 	bash -O extglob -c '$(SYMLINK) $(OUTPUT_DIR_ARTIFACTS) $(INSTALL_DIR)/koreader/'
 ifneq (,$(EMULATE_READER))
-	@echo "[*] install front spec only for the emulator"
+	@echo "[*] Install front spec only for the emulator"
 	$(SYMLINK) spec $(INSTALL_DIR)/koreader/spec/front
 	$(SYMLINK) test $(INSTALL_DIR)/koreader/spec/front/unit/data
 endif
@@ -112,10 +171,6 @@ endif
 	! test -L $(INSTALL_DIR)/koreader/data || rm $(INSTALL_DIR)/koreader/data
 	install -d $(INSTALL_DIR)/koreader/data
 	$(SYMLINK) $(strip $(DATADIR_FILES)) $(INSTALL_DIR)/koreader/data/
-ifneq (,$(IS_RELEASE))
-	@echo "[*] Clean up, remove unused files for releases"
-	rm -rf $(INSTALL_DIR)/koreader/data/{cr3.ini,desktop,devices,dict,manual,tessdata}
-endif
 
 base: base-all
 
@@ -198,3 +253,5 @@ doc:
 .PHONY: $(PHONY)
 
 include $(KOR_BASE)/Makefile
+
+# vim: foldmethod=marker foldlevel=0
diff --git a/make/android.mk b/make/android.mk
index 40b87e3f395c..9b37262e4202 100644
--- a/make/android.mk
+++ b/make/android.mk
@@ -42,6 +42,12 @@ ANDROID_DIR = $(PLATFORM_DIR)/android
 ANDROID_LAUNCHER_DIR = $(ANDROID_DIR)/luajit-launcher
 ANDROID_LAUNCHER_BUILD = $(INSTALL_DIR)/luajit-launcher
 ANDROID_ASSETS = $(ANDROID_LAUNCHER_BUILD)/assets
+# Assets compression method:
+# - LZMA/LZMA2: `-m0=lzma2 -mx=9`
+# - LZMA/LZMA2 (7z >= 17.02, fast version): `-m0=flzma2 -mx=9`
+# - ZSTD (7z >= 17.02, LZMA still used for archive headers): `-m0=zstd -mx=16`
+# - ZSTD (7z >= 17.02): `-m0=zstd -mhc=off -mx=16`
+ANDROID_ASSETS_COMPRESSION ?= -m0=lzma2 -mx=9
 ANDROID_LIBS = $(ANDROID_LAUNCHER_BUILD)/libs/$(ANDROID_ABI)
 ANDROID_FLAVOR ?= Rocks
 
@@ -61,6 +67,22 @@ else
   ANDROID_ABI ?= armeabi-v7a
 endif
 
+define UPDATE_PATH_EXCLUDES +=
+plugins/SSH.koplugin
+plugins/autofrontlight.koplugin
+plugins/hello.koplugin
+plugins/timesync.koplugin
+tools
+endef
+
+define UPDATE_GLOBAL_EXCLUDES +=
+README.md
+COPYING
+LICENSE*
+*license.txt
+NOTICE
+endef
+
 androiddev: update
 	$(MAKE) -C $(ANDROID_LAUNCHER_DIR) dev
 
@@ -83,35 +105,14 @@ update: all
 	# binaries are stored as shared libraries to prevent W^X exception on Android 10+
 	# https://developer.android.com/about/versions/10/behavior-changes-10#execute-permission
 	llvm-strip --strip-unneeded $(INSTALL_DIR)/koreader/sdcv -o $(ANDROID_LIBS)/libsdcv.so
-	# assets are compressed manually and stored inside the APK.
+	# Assets are compressed manually and stored inside the APK.
 	cd $(INSTALL_DIR)/koreader && \
-		./tools/mk7z.sh \
-		$(abspath $(ANDROID_ASSETS)/module/koreader.7z) \
-		"$$(git show -s --format='%ci')" \
-		-m0=lzma2 -mx=9 \
-		-- . \
-		'-x!cache' \
-		'-x!clipboard' \
-		'-x!data/dict' \
-		'-x!data/tessdata' \
-		'-x!history' \
-		'-x!l10n/templates' \
-		'-x!libs' \
-		'-x!ota' \
-		'-x!resources/fonts*' \
-		'-x!resources/icons/src*' \
-		'-x!rocks/bin' \
-		'-x!rocks/lib/luarocks' \
-		'-x!screenshots' \
-		'-x!sdcv' \
-		'-x!spec' \
-		'-x!tools' \
-		'-xr!.*' \
-		'-xr!COPYING' \
-		'-xr!NOTES.txt' \
-		'-xr!NOTICE' \
-		'-xr!README.md' \
-		;
+	  ./tools/mkrelease.sh \
+	  $(if $(PARALLEL_JOBS),--jobs $(PARALLEL_JOBS)) \
+	  --epoch="$$(git show -s --format='%ci')" \
+	  --options='$(ANDROID_ASSETS_COMPRESSION)' \
+	  $(abspath $(ANDROID_ASSETS)/module/koreader.7z) \
+	  . '-x!libs' '-x!sdcv' $(release_excludes)
 	# Note: we filter out the `--debug=…` make flag so the old
 	# crummy version provided by the NDK does not blow a gasket.
 	env \
diff --git a/make/appimage.mk b/make/appimage.mk
index 39b4ccd2ff39..cca4e557e270 100644
--- a/make/appimage.mk
+++ b/make/appimage.mk
@@ -1,31 +1,36 @@
 APPIMAGE_DIR = $(PLATFORM_DIR)/appimage
 
 APPIMAGETOOL = appimagetool-x86_64.AppImage
-APPIMAGETOOL_URL = https://github.com/AppImage/AppImageKit/releases/download/13/appimagetool-x86_64.AppImage
+APPIMAGETOOL_URL = https://github.com/AppImage/AppImageKit/releases/download/13/$(APPIMAGETOOL)
+
+KOREADER_APPIMAGE = koreader-$(DIST)-$(MACHINE)-$(VERSION).AppImage
+
+UBUNTU_LIBBSD = /lib/x86_64-linux-gnu/libbsd.so.0
+
+define UPDATE_PATH_EXCLUDES +=
+plugins/SSH.koplugin
+plugins/autofrontlight.koplugin
+plugins/timesync.koplugin
+$(filter-out tools/trace_require.lua tools/wbuilder.lua,$(wildcard tools/*))
+endef
 
 update: all
-	# remove old package if any
-	rm -f koreader-appimage-$(MACHINE)-$(VERSION).appimage
-	$(SYMLINK) $(APPIMAGE_DIR)/AppRun $(INSTALL_DIR)/koreader/
-	$(SYMLINK) $(APPIMAGE_DIR)/koreader.desktop $(INSTALL_DIR)/koreader/
-	$(SYMLINK) resources/koreader.png $(INSTALL_DIR)/koreader/
-	sed -e 's/%%VERSION%%/$(VERSION)/' -e 's/%%DATE%%/$(RELEASE_DATE)/' $(PLATFORM_DIR)/common/koreader.metainfo.xml >$(INSTALL_DIR)/koreader/koreader.appdata.xml
-	# also copy libbsd.so.0, cf. https://github.com/koreader/koreader/issues/4627
-	$(SYMLINK) /lib/x86_64-linux-gnu/libbsd.so.0 $(INSTALL_DIR)/koreader/libs/
-ifeq ("$(wildcard $(APPIMAGETOOL))","")
-	# download appimagetool
-	wget "$(APPIMAGETOOL_URL)"
-	chmod a+x "$(APPIMAGETOOL)"
+	cd $(INSTALL_DIR)/koreader && '$(abspath tools/mkrelease.sh)' ../appimage/ . $(release_excludes)
+	cp $(APPIMAGE_DIR)/{AppRun,koreader.desktop} resources/koreader.png $(INSTALL_DIR)/appimage/
+	sed -e 's/%%VERSION%%/$(VERSION)/' -e 's/%%DATE%%/$(RELEASE_DATE)/' $(PLATFORM_DIR)/common/koreader.metainfo.xml >$(INSTALL_DIR)/appimage/koreader.appdata.xml
+	# Also copy libbsd.so.0 (cf. https://github.com/koreader/koreader/issues/4627).
+ifeq (,$(wildcard $(UBUNTU_LIBBSD)))
+	# Only warn if it's missing (e.g. when testing on a non-Ubuntu distribution).
+	echo 'WARNING: not bundling missing $(UBUNTU_LIBBSD)' 1>&2
+else
+	cp $(UBUNTU_LIBBSD) $(INSTALL_DIR)/appimage/libs/
+endif
+ifeq (,$(wildcard $(APPIMAGETOOL)))
+	# Download appimagetool.
+	wget '$(APPIMAGETOOL_URL)'
+	chmod a+x ./$(APPIMAGETOOL)
 endif
-	cd $(INSTALL_DIR) && pwd && \
-		rm -rf tmp && mkdir -p tmp && \
-		cp -Lr koreader tmp && \
-		rm -rf tmp/koreader/ota && \
-		rm -rf tmp/koreader/resources/icons/src && \
-		rm -rf tmp/koreader/spec
-	# generate AppImage
-	cd $(INSTALL_DIR)/tmp && \
-		ARCH=x86_64 "$$OLDPWD/$(APPIMAGETOOL)" --appimage-extract-and-run koreader && \
-		mv *.AppImage ../../koreader-$(DIST)-$(MACHINE)-$(VERSION).AppImage
+	# Generate AppImage.
+	ARCH=x86_64 ./$(APPIMAGETOOL) --appimage-extract-and-run $(INSTALL_DIR)/appimage $(KOREADER_APPIMAGE)
 
 PHONY += update
diff --git a/make/cervantes.mk b/make/cervantes.mk
index fbf93db7209f..eb2cb898d008 100644
--- a/make/cervantes.mk
+++ b/make/cervantes.mk
@@ -2,32 +2,21 @@ CERVANTES_DIR = $(PLATFORM_DIR)/cervantes
 CERVANTES_PACKAGE = koreader-cervantes$(KODEDUG_SUFFIX)-$(VERSION).zip
 CERVANTES_PACKAGE_OTA = koreader-cervantes$(KODEDUG_SUFFIX)-$(VERSION).targz
 
+define UPDATE_PATH_EXCLUDES +=
+tools
+endef
+
 update: all
 	# ensure that the binaries were built for ARM
 	file --dereference $(INSTALL_DIR)/koreader/luajit | grep ARM
 	# remove old package if any
 	rm -f $(CERVANTES_PACKAGE)
 	# Cervantes launching scripts
-	cp $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader/spinning_zsync.sh
-	cp $(CERVANTES_DIR)/*.sh $(INSTALL_DIR)/koreader
-	cp $(CERVANTES_DIR)/spinning_zsync $(INSTALL_DIR)/koreader
-	# create new package
-	cd $(INSTALL_DIR) && \
-		zip -9 -r \
-			../$(CERVANTES_PACKAGE) \
-			koreader -x "koreader/resources/fonts/*" \
-			"koreader/resources/icons/src/*" "koreader/spec/*" \
-			$(ZIP_EXCLUDE)
-	# generate update package index file
-	zipinfo -1 $(CERVANTES_PACKAGE) > \
-		$(INSTALL_DIR)/koreader/ota/package.index
-	echo "koreader/ota/package.index" >> $(INSTALL_DIR)/koreader/ota/package.index
-	# update index file in zip package
-	cd $(INSTALL_DIR) && zip -u ../$(CERVANTES_PACKAGE) \
-	koreader/ota/package.index
-	# make gzip cervantes update for zsync OTA update
-	cd $(INSTALL_DIR) && \
-	tar --hard-dereference -I"gzip --rsyncable" -cah --no-recursion -f ../$(CERVANTES_PACKAGE_OTA) \
-	-T koreader/ota/package.index
+	$(SYMLINK) $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader/spinning_zsync.sh
+	$(SYMLINK) $(CERVANTES_DIR)/*.sh $(INSTALL_DIR)/koreader
+	$(SYMLINK) $(CERVANTES_DIR)/spinning_zsync $(INSTALL_DIR)/koreader
+	# Create packages.
+	$(strip $(call mkupdate,$(CERVANTES_PACKAGE)))
+	$(strip $(call mkupdate,$(CERVANTES_PACKAGE_OTA)))
 
 PHONY += update
diff --git a/make/kindle.mk b/make/kindle.mk
index a73f886ef3c0..d796002160b5 100644
--- a/make/kindle.mk
+++ b/make/kindle.mk
@@ -1,18 +1,20 @@
 KINDLE_DIR = $(PLATFORM_DIR)/kindle
 KINDLE_PACKAGE = koreader-$(DIST)$(KODEDUG_SUFFIX)-$(VERSION).zip
+# Note: the targz extension is intended to keep ISP from caching the file (Cf. koreader#1644).
 KINDLE_PACKAGE_OTA = koreader-$(DIST)$(KODEDUG_SUFFIX)-$(VERSION).targz
-ZIP_EXCLUDE = -x "*.swp" -x "*.swo" -x "*.orig" -x "*.un~"
 
 # Don't bundle launchpad on touch devices..
 ifeq ($(TARGET), kindle-legacy)
   KINDLE_LEGACY_LAUNCHER = launchpad
 endif
 
+define UPDATE_PATH_EXCLUDES +=
+tools
+endef
+
 update: all
 	# ensure that the binaries were built for ARM
 	file --dereference $(INSTALL_DIR)/koreader/luajit | grep ARM
-	# remove old package if any
-	rm -f $(KINDLE_PACKAGE)
 	# Kindle launching scripts
 	$(SYMLINK) $(KINDLE_DIR)/extensions $(INSTALL_DIR)/
 	$(SYMLINK) $(KINDLE_DIR)/launchpad $(INSTALL_DIR)/
@@ -21,26 +23,8 @@ update: all
 	$(SYMLINK) $(KINDLE_DIR)/libkohelper.sh $(INSTALL_DIR)/extensions/koreader/bin/
 	$(SYMLINK) $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader/
 	$(SYMLINK) $(KINDLE_DIR)/wmctrl $(INSTALL_DIR)/koreader/
-	# create new package
-	cd $(INSTALL_DIR) && pwd && \
-		zip -9 -r \
-			../$(KINDLE_PACKAGE) \
-			extensions koreader $(KINDLE_LEGACY_LAUNCHER) \
-			-x "koreader/resources/fonts/*" "koreader/ota/*" \
-			"koreader/resources/icons/src/*" "koreader/spec/*" \
-			$(ZIP_EXCLUDE)
-	# generate kindleupdate package index file
-	zipinfo -1 $(KINDLE_PACKAGE) > \
-		$(INSTALL_DIR)/koreader/ota/package.index
-	echo "koreader/ota/package.index" >> $(INSTALL_DIR)/koreader/ota/package.index
-	# update index file in zip package
-	cd $(INSTALL_DIR) && zip -u ../$(KINDLE_PACKAGE) \
-		koreader/ota/package.index
-	# make gzip kindleupdate for zsync OTA update
-	# note that the targz file extension is intended to keep ISP from caching
-	# the file, see koreader#1644.
-	cd $(INSTALL_DIR) && \
-		tar --hard-dereference -I"gzip --rsyncable" -cah --no-recursion -f ../$(KINDLE_PACKAGE_OTA) \
-		-T koreader/ota/package.index
+	# Create packages.
+	$(strip $(call mkupdate,$(KINDLE_PACKAGE))) extensions $(KINDLE_LEGACY_LAUNCHER)
+	$(strip $(call mkupdate,$(KINDLE_PACKAGE_OTA))) extensions $(KINDLE_LEGACY_LAUNCHER)
 
 PHONY += update
diff --git a/make/kobo.mk b/make/kobo.mk
index 2bce8f0f144b..36764fd01d4b 100644
--- a/make/kobo.mk
+++ b/make/kobo.mk
@@ -2,32 +2,19 @@ KOBO_DIR = $(PLATFORM_DIR)/kobo
 KOBO_PACKAGE = koreader-$(DIST)$(KODEDUG_SUFFIX)-$(VERSION).zip
 KOBO_PACKAGE_OTA = koreader-$(DIST)$(KODEDUG_SUFFIX)-$(VERSION).targz
 
+define UPDATE_PATH_EXCLUDES +=
+$(filter-out tools/kobo%,$(wildcard tools/*))
+endef
+
 update: all
 	# ensure that the binaries were built for ARM
 	file --dereference $(INSTALL_DIR)/koreader/luajit | grep ARM
-	# remove old package if any
-	rm -f $(KOBO_PACKAGE)
 	# Kobo launching scripts
-	cp $(KOBO_DIR)/koreader.png $(INSTALL_DIR)/koreader.png
-	cp $(KOBO_DIR)/*.sh $(INSTALL_DIR)/koreader
-	cp $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader
-	# create new package
-	cd $(INSTALL_DIR) && \
-		zip -9 -r \
-			../$(KOBO_PACKAGE) \
-			koreader -x "koreader/resources/fonts/*" \
-			"koreader/resources/icons/src/*" "koreader/spec/*" \
-			$(ZIP_EXCLUDE)
-	# generate koboupdate package index file
-	zipinfo -1 $(KOBO_PACKAGE) > \
-		$(INSTALL_DIR)/koreader/ota/package.index
-	echo "koreader/ota/package.index" >> $(INSTALL_DIR)/koreader/ota/package.index
-	# update index file in zip package
-	cd $(INSTALL_DIR) && zip -u ../$(KOBO_PACKAGE) \
-		koreader/ota/package.index koreader.png README_kobo.txt
-	# make gzip koboupdate for zsync OTA update
-	cd $(INSTALL_DIR) && \
-		tar --hard-dereference -I"gzip --rsyncable" -cah --no-recursion -f ../$(KOBO_PACKAGE_OTA) \
-		-T koreader/ota/package.index
+	$(SYMLINK) $(KOBO_DIR)/koreader.png $(INSTALL_DIR)/
+	$(SYMLINK) $(KOBO_DIR)/*.sh $(INSTALL_DIR)/koreader/
+	$(SYMLINK) $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader/
+	# Create packages.
+	$(strip $(call mkupdate,--manifest-transform=/^koreader\.png$$/d $(KOBO_PACKAGE))) koreader.png
+	$(strip $(call mkupdate,$(KOBO_PACKAGE_OTA)))
 
 PHONY += update
diff --git a/make/linux.mk b/make/linux.mk
index b00a6c2fe7dd..f45b79063d55 100644
--- a/make/linux.mk
+++ b/make/linux.mk
@@ -1,44 +1,36 @@
 LINUX_DIR = $(PLATFORM_DIR)/linux
-LINUX_PACKAGE:=koreader-linux-$(LINUX_ARCH_NAME)$(KODEDUG_SUFFIX)-$(VERSION).tar.xz
+LINUX_PACKAGE = koreader-linux-$(LINUX_ARCH_NAME)$(KODEDUG_SUFFIX)-$(VERSION).tar.xz
+LINUX_PACKAGE_COMPRESSION_LEVEL ?= 9
 
-GLIBC_VERSION := $(shell ldd --version | sed -n '1s/.* \([0-9.]\+\)$$/\1/p')
+GLIBC_VERSION = $(shell ldd --version | sed -n '1s/.* \([0-9.]\+\)$$/\1/p')
+
+define UPDATE_PATH_EXCLUDES +=
+plugins/SSH.koplugin
+plugins/autofrontlight.koplugin
+plugins/timesync.koplugin
+$(filter-out tools/trace_require.lua tools/wbuilder.lua,$(wildcard tools/*))
+endef
 
 update: all
-	mkdir -pv \
-		$(INSTALL_DIR)/linux/bin \
-		$(INSTALL_DIR)/linux/lib \
-		$(INSTALL_DIR)/linux/share/pixmaps \
-		$(INSTALL_DIR)/linux/share/metainfo \
-		$(INSTALL_DIR)/linux/share/applications \
-		$(INSTALL_DIR)/linux/share/doc/koreader \
-		$(INSTALL_DIR)/linux/share/man/man1
+	rm -rf $(INSTALL_DIR)/linux
+	mkdir -p $(INSTALL_DIR)/linux/{bin,lib,share/{applications,doc/koreader,man/man1,metainfo,pixmaps}}
 	sed -e 's/%%VERSION%%/$(VERSION)/g' -e 's/%%DATE%%/$(RELEASE_DATE)/' $(PLATFORM_DIR)/common/koreader.metainfo.xml >$(INSTALL_DIR)/linux/share/metainfo/koreader.metainfo.xml
-	cp -pv resources/koreader.png $(INSTALL_DIR)/linux/share/pixmaps
-	cp -pv $(LINUX_DIR)/koreader.desktop $(INSTALL_DIR)/linux/share/applications
-	cp -pv $(LINUX_DIR)/copyright COPYING $(INSTALL_DIR)/linux/share/doc/koreader
-	cp -pv $(LINUX_DIR)/koreader.sh $(INSTALL_DIR)/linux/bin/koreader
-	cp -Lr $(INSTALL_DIR)/koreader $(INSTALL_DIR)/linux/lib
-	gzip -cn9 $(LINUX_DIR)/koreader.1 > $(INSTALL_DIR)/linux/share/man/man1/koreader.1.gz
-	chmod 644 \
-		$(INSTALL_DIR)/linux/share/doc/koreader/copyright \
-		$(INSTALL_DIR)/linux/share/man/man1/koreader.1.gz
-	rm -rf \
-		$(INSTALL_DIR)/linux/lib/koreader/{ota,cache,clipboard,screenshots,spec,tools,resources/fonts,resources/icons/src}
-
-	# remove leftovers
-	find $(INSTALL_DIR)/linux -type f \( -name ".git" -o -name ".gitignore" -o -name "discovery2spore" -o -name "wadl2spore" -o -name "*.txt" -o -name "LICENSE*" -o -name "NOTICE" -o -name "README.md" \) -print0 | xargs -0 rm -rf
-	find $(INSTALL_DIR)/linux -type d \( -name "test" -o -name ".github" \) -print0 | xargs -0 rm -rf
-
-	# add instructions
+	$(SYMLINK) $(LINUX_DIR)/koreader.sh $(INSTALL_DIR)/linux/bin/koreader
+	$(SYMLINK) $(INSTALL_DIR)/koreader $(INSTALL_DIR)/linux/lib/
+	$(SYMLINK) resources/koreader.png $(INSTALL_DIR)/linux/share/pixmaps/
+	$(SYMLINK) $(LINUX_DIR)/koreader.desktop $(INSTALL_DIR)/linux/share/applications/
+	$(SYMLINK) $(LINUX_DIR)/copyright COPYING $(INSTALL_DIR)/linux/share/doc/koreader/
+	gzip -cn9 $(LINUX_DIR)/koreader.1 >$(INSTALL_DIR)/linux/share/man/man1/koreader.1.gz
+	# Add instructions.
 	sed -e 's/%%VERSION%%/$(VERSION)/' \
 		-e 's/%%ARCH%%/$(LINUX_ARCH_NAME)/' \
 		-e 's/%%ABI%%/$(GLIBC_VERSION)/' \
 		 $(LINUX_DIR)/instructions.txt >$(INSTALL_DIR)/linux/README.md
-
-	# fix permissions
-	chmod -R u=rwX,og=rX $(INSTALL_DIR)/linux
-	XZ_OPT=9 tar -C $(INSTALL_DIR)/linux -cvJf $(LINUX_PACKAGE) .
-
-	rm -rf $(INSTALL_DIR)/linux
+	# Create archive.
+	cd $(INSTALL_DIR)/linux && \
+		'$(abspath tools/mkrelease.sh)' \
+		$(if $(PARALLEL_JOBS),--jobs $(PARALLEL_JOBS)) \
+		--options=-$(LINUX_PACKAGE_COMPRESSION_LEVEL) \
+		'$(abspath $(LINUX_PACKAGE))' . $(call release_excludes,lib/koreader/)
 
 PHONY += update
diff --git a/make/macos.mk b/make/macos.mk
index f34bfca6055c..ee6c5fb9763e 100644
--- a/make/macos.mk
+++ b/make/macos.mk
@@ -1,14 +1,20 @@
 MACOS_DIR = $(PLATFORM_DIR)/mac
 
+define UPDATE_PATH_EXCLUDES +=
+plugins/SSH.koplugin
+plugins/autofrontlight.koplugin
+plugins/hello.koplugin
+plugins/timesync.koplugin
+tools
+endef
+
 update: all
-	mkdir -p \
-		$(INSTALL_DIR)/bundle/Contents/MacOS \
-		$(INSTALL_DIR)/bundle/Contents/Resources
+	mkdir -p $(INSTALL_DIR)/bundle/Contents/{MacOS,Resources}
 	cp -pv $(MACOS_DIR)/koreader.icns $(INSTALL_DIR)/bundle/Contents/Resources/icon.icns
-	cp -LR $(INSTALL_DIR)/koreader $(INSTALL_DIR)/bundle/Contents
-	cp -pRv $(MACOS_DIR)/menu.xml $(INSTALL_DIR)/bundle/Contents/MainMenu.xib
-	ibtool --compile "$(INSTALL_DIR)/bundle/Contents/Resources/Base.lproj/MainMenu.nib" "$(INSTALL_DIR)/bundle/Contents/MainMenu.xib"
-	rm -rfv "$(INSTALL_DIR)/bundle/Contents/MainMenu.xib"
+	cd $(INSTALL_DIR)/koreader && '$(abspath tools/mkrelease.sh)' ../bundle/Contents/koreader/ . $(release_excludes)
+	cp -pv $(MACOS_DIR)/menu.xml $(INSTALL_DIR)/bundle/Contents/MainMenu.xib
+	ibtool --compile $(INSTALL_DIR)/bundle/Contents/Resources/Base.lproj/MainMenu.nib $(INSTALL_DIR)/bundle/Contents/MainMenu.xib
+	rm -vf $(INSTALL_DIR)/bundle/Contents/MainMenu.xib
 	$(CURDIR)/platform/mac/do_mac_bundle.sh $(INSTALL_DIR)
 
 PHONY += update
diff --git a/make/pocketbook.mk b/make/pocketbook.mk
index 987288ff35b0..f84ed4e1e817 100644
--- a/make/pocketbook.mk
+++ b/make/pocketbook.mk
@@ -2,42 +2,23 @@ POCKETBOOK_DIR = $(PLATFORM_DIR)/pocketbook
 PB_PACKAGE = koreader-pocketbook$(KODEDUG_SUFFIX)-$(VERSION).zip
 PB_PACKAGE_OTA = koreader-pocketbook$(KODEDUG_SUFFIX)-$(VERSION).targz
 
+define UPDATE_PATH_EXCLUDES +=
+tools
+endef
+
 update: all
 	# ensure that the binaries were built for ARM
 	file --dereference $(INSTALL_DIR)/koreader/luajit | grep ARM
-	# remove old package if any
-	rm -f $(PB_PACKAGE)
 	# Pocketbook launching scripts
+	rm -rf $(INSTALL_DIR)/{applications,system}
 	mkdir -p $(INSTALL_DIR)/applications
 	mkdir -p $(INSTALL_DIR)/system/bin
-	cp $(POCKETBOOK_DIR)/koreader.app $(INSTALL_DIR)/applications
-	cp $(POCKETBOOK_DIR)/system_koreader.app $(INSTALL_DIR)/system/bin/koreader.app
-	cp $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader
-	cp -rfL $(INSTALL_DIR)/koreader $(INSTALL_DIR)/applications
-	find $(INSTALL_DIR)/applications/koreader \
-		-type f \( -name "*.gif" -o -name "*.html" -o -name "*.md" -o -name "*.txt" \) \
-		-exec rm -vf {} \;
-	# create new package
-	cd $(INSTALL_DIR) && \
-		zip -9 -r \
-			../$(PB_PACKAGE) \
-			applications -x "applications/koreader/resources/fonts/*" \
-			"applications/koreader/resources/icons/src/*" "applications/koreader/spec/*" \
-			$(ZIP_EXCLUDE)
-	# generate pocketbook package index file
-	zipinfo -1 $(PB_PACKAGE) > \
-		$(INSTALL_DIR)/applications/koreader/ota/package.index
-	echo "applications/koreader/ota/package.index" >> \
-		$(INSTALL_DIR)/applications/koreader/ota/package.index
-	# hack file path when running tar in parent directory of koreader
-	sed -i -e 's/^/..\//' \
-		$(INSTALL_DIR)/applications/koreader/ota/package.index
-	# update index file in zip package
-	cd $(INSTALL_DIR) && zip -ru ../$(PB_PACKAGE) \
-		applications/koreader/ota/package.index system
-	# make gzip pbupdate for zsync OTA update
-	cd $(INSTALL_DIR)/applications && \
-		tar --hard-dereference -I"gzip --rsyncable" -cah --no-recursion -f ../../$(PB_PACKAGE_OTA) \
-		-T koreader/ota/package.index
+	$(SYMLINK) $(POCKETBOOK_DIR)/koreader.app $(INSTALL_DIR)/applications/
+	$(SYMLINK) $(POCKETBOOK_DIR)/system_koreader.app $(INSTALL_DIR)/system/bin/koreader.app
+	$(SYMLINK) $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader/
+	$(SYMLINK) $(INSTALL_DIR)/koreader $(INSTALL_DIR)/applications/
+	# Create packages.
+	$(strip $(call mkupdate,--manifest-transform=/^system/d;s/^/..\// $(PB_PACKAGE),applications/koreader)) applications system
+	$(strip $(call mkupdate,--manifest-transform=s/^/..\// $(PB_PACKAGE_OTA),applications/koreader)) applications
 
 PHONY += update
diff --git a/make/remarkable.mk b/make/remarkable.mk
index 76e09d2711bb..f85ad0a2072a 100644
--- a/make/remarkable.mk
+++ b/make/remarkable.mk
@@ -2,31 +2,19 @@ REMARKABLE_DIR = $(PLATFORM_DIR)/remarkable
 REMARKABLE_PACKAGE = koreader-remarkable$(KODEDUG_SUFFIX)-$(VERSION).zip
 REMARKABLE_PACKAGE_OTA = koreader-remarkable$(KODEDUG_SUFFIX)-$(VERSION).targz
 
+define UPDATE_PATH_EXCLUDES +=
+plugins/SSH.koplugin
+tools
+endef
+
 update: all
 	# ensure that the binaries were built for ARM
 	file --dereference $(INSTALL_DIR)/koreader/luajit | grep ARM
-	# remove old package if any
-	rm -f $(REMARKABLE_PACKAGE)
 	# Remarkable scripts
-	cp $(REMARKABLE_DIR)/* $(INSTALL_DIR)/koreader
-	cp $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader
-	# create new package
-	cd $(INSTALL_DIR) && \
-	        zip -9 -r \
-	                ../$(REMARKABLE_PACKAGE) \
-	                koreader -x "koreader/resources/fonts/*" \
-	                "koreader/resources/icons/src/*" "koreader/spec/*" \
-	                $(ZIP_EXCLUDE)
-	# generate update package index file
-	zipinfo -1 $(REMARKABLE_PACKAGE) > \
-	        $(INSTALL_DIR)/koreader/ota/package.index
-	echo "koreader/ota/package.index" >> $(INSTALL_DIR)/koreader/ota/package.index
-	# update index file in zip package
-	cd $(INSTALL_DIR) && zip -u ../$(REMARKABLE_PACKAGE) \
-	        koreader/ota/package.index
-	# make gzip remarkable update for zsync OTA update
-	cd $(INSTALL_DIR) && \
-	        tar -I"gzip --rsyncable" -cah --no-recursion -f ../$(REMARKABLE_PACKAGE_OTA) \
-	        -T koreader/ota/package.index
+	$(SYMLINK) $(REMARKABLE_DIR)/* $(INSTALL_DIR)/koreader/
+	$(SYMLINK) $(COMMON_DIR)/spinning_zsync $(INSTALL_DIR)/koreader/
+	# Create packages.
+	$(strip $(call mkupdate,$(REMARKABLE_PACKAGE)))
+	$(strip $(call mkupdate,$(REMARKABLE_PACKAGE_OTA)))
 
 PHONY += update
diff --git a/make/sony-prstux.mk b/make/sony-prstux.mk
index 724e228d23b0..94b00cc54fc7 100644
--- a/make/sony-prstux.mk
+++ b/make/sony-prstux.mk
@@ -2,30 +2,18 @@ SONY_PRSTUX_DIR = $(PLATFORM_DIR)/sony-prstux
 SONY_PRSTUX_PACKAGE = koreader-sony-prstux$(KODEDUG_SUFFIX)-$(VERSION).zip
 SONY_PRSTUX_PACKAGE_OTA = koreader-sony-prstux$(KODEDUG_SUFFIX)-$(VERSION).targz
 
+define UPDATE_PATH_EXCLUDES +=
+plugins/SSH.koplugin
+tools
+endef
+
 update: all
 	# ensure that the binaries were built for ARM
 	file --dereference $(INSTALL_DIR)/koreader/luajit | grep ARM
-	# remove old package if any
-	rm -f $(SONY_PRSTUX_PACKAGE)
 	# Sony PRSTUX launching scripts
-	cp $(SONY_PRSTUX_DIR)/*.sh $(INSTALL_DIR)/koreader
-	# create new package
-	cd $(INSTALL_DIR) && \
-	        zip -9 -r \
-	                ../$(SONY_PRSTUX_PACKAGE) \
-	                koreader -x "koreader/resources/fonts/*" \
-	                "koreader/resources/icons/src/*" "koreader/spec/*" \
-	                $(ZIP_EXCLUDE)
-	# generate update package index file
-	zipinfo -1 $(SONY_PRSTUX_PACKAGE) > \
-	        $(INSTALL_DIR)/koreader/ota/package.index
-	echo "koreader/ota/package.index" >> $(INSTALL_DIR)/koreader/ota/package.index
-	# update index file in zip package
-	cd $(INSTALL_DIR) && zip -u ../$(SONY_PRSTUX_PACKAGE) \
-	        koreader/ota/package.index
-	# make gzip sonyprstux update for zsync OTA update
-	cd $(INSTALL_DIR) && \
-	        tar --hard-dereference -I"gzip --rsyncable" -cah --no-recursion -f ../$(SONY_PRSTUX_PACKAGE_OTA) \
-	        -T koreader/ota/package.index
+	$(SYMLINK) $(SONY_PRSTUX_DIR)/*.sh $(INSTALL_DIR)/koreader
+	# Create packages.
+	$(strip $(call mkupdate,$(SONY_PRSTUX_PACKAGE)))
+	$(strip $(call mkupdate,$(SONY_PRSTUX_PACKAGE_OTA)))
 
 PHONY += update
diff --git a/platform/mac/do_mac_bundle.sh b/platform/mac/do_mac_bundle.sh
index 029d679f708a..92eb70a02f5f 100755
--- a/platform/mac/do_mac_bundle.sh
+++ b/platform/mac/do_mac_bundle.sh
@@ -131,11 +131,6 @@ pushd "${APP_PATH}/Contents/koreader"
 lipo /usr/bin/tar -extract_family "${APP_ARCH}" -output tar
 mv COPYING README.md ../Resources/
 mv koreader ../MacOS/koreader
-rm -rf cache clipboard history ota \
-    l10n/.git l10n/.tx l10n/templates l10n/LICENSE l10n/Makefile l10n/README.md \
-    plugins/SSH.koplugin plugins/hello.koplugin plugins/timesync.koplugin \
-    plugins/autofrontlight.koplugin resources/fonts resources/icons/src \
-    rocks/bin rocks/lib/luarocks screenshots spec tools
 
 # Adjust reader.lua a bit.
 sed '1d' reader.lua >tempfile
@@ -162,6 +157,6 @@ codesign --force --deep -s - "${APP_BUNDLE}.app"
 
 # Package as 7z reduces size from 80MB to 30MB.
 if command_exists "7z"; then
-    7z a -l -m0=lzma2 -mx=9 "${APP_BUNDLE}-${APP_ARCH}-${VERSION}.7z" "${APP_BUNDLE}.app"
-    rm -rfv "${APP_BUNDLE}.app"
+    7z a -l -m0=flzma2 -mx=9 "${APP_BUNDLE}-${APP_ARCH}-${VERSION}.7z" "${APP_BUNDLE}.app"
+    rm -rf "${APP_BUNDLE}.app"
 fi
diff --git a/tools/mk7z.sh b/tools/mk7z.sh
deleted file mode 100755
index 77584cfb9758..000000000000
--- a/tools/mk7z.sh
+++ /dev/null
@@ -1,93 +0,0 @@
-#!/usr/bin/env bash
-
-set -eo pipefail
-# set -x
-
-[[ $# -ge 3 ]]
-archive="$(realpath "$1")"
-epoch="$2"
-shift 2
-options=()
-for a in "$@"; do
-    shift
-    case "${a}" in
-        --) break ;;
-        -*) options+=("${a}") ;;
-        *) break ;;
-    esac
-done
-[[ $# -gt 0 ]]
-patterns=("$@")
-
-# We need to use the full path to the executable to avoid
-# a weird issue when using the p7zip project pre-built
-# binary (`Can't load './7z.dll' (7z.so)...`).
-sevenzip="$(which 7z)"
-
-# echo "archive : ${archive}"
-# echo "epoch   : ${epoch}"
-# echo "options : ${options[@]}"
-# echo "patterns: ${patterns[@]}"
-
-tmpdir="$(mktemp -d -t tmp7z.XXXXXXXXXX)"
-trap 'rm -rf "${tmpdir}"' EXIT
-
-manifest="${tmpdir}/manifest"
-
-# Detect if that version of 7z deferences symlinks by default.
-sevenzip_manifest_cmd=("${sevenzip}" -ba h)
-ln -s /dev/null "${tmpdir}/symlink"
-checksum="$("${sevenzip_manifest_cmd[@]}" "${tmpdir}/symlink" | awk '{ print $1 }')"
-if [[ "${checksum}" != '00000000' ]]; then
-    sevenzip_manifest_cmd+=(-l)
-fi
-rm -f "${tmpdir}/symlink"
-
-# Note: remove trailing `/` appended to directories in some 7z versions.
-"${sevenzip_manifest_cmd[@]}" "${patterns[@]}" |
-    awk '{ if ($3!="") print $3, $2, $1; else { gsub("/$", "", $1); print $1 } }' |
-    sort >"${manifest}"
-
-# cat "${manifest}" | less
-
-if [[ -r "${archive}" ]]; then
-    if diff --brief --label 'in archive' \
-        <(
-            "${sevenzip}" -slt l "${archive}" |
-                awk '
-                    /^([^=]+) = / { entry[$1] = $3; }
-                    /^CRC =/ { if ($3!="") print entry["Path"], entry["Size"], $3; else print entry["Path"] }
-                    ' | sort
-        ) --label 'to add' "${manifest}"; then
-        exit
-    fi
-    # There's no 7z option to overwrite the archive
-    # if it already exists (instead of updating it)…
-    rm -f "${archive}"
-fi
-
-# Extract list of paths from manifest.
-rev <"${manifest}" | cut -f3- -d' ' | rev >"${tmpdir}/paths"
-# Quick sanity check: no path outside the current directory.
-if grep '^(/|\.\./)' <"${tmpdir}/paths"; then
-    echo "^ some paths are outside the current directory!"
-    exit 1
-fi
-
-# Make a copy of everything so we can later
-# patch timestamp to ensure reproducibility.
-mkdir "${tmpdir}/contents"
-# We want to copy "empty" (with ignored files) directories.
-tar --dereference --no-recursion --create \
-    --verbatim-files-from --files-from="${tmpdir}/paths" |
-    tar --extract --directory="${tmpdir}/contents"
-
-cd "${tmpdir}/contents"
-
-# Fix timestamps.
-find . -depth -print0 | xargs -0 touch --date="${epoch}"
-
-# And create the final archive.
-"${sevenzip}" -mqs "${options[@]}" a "${archive}" .
-
-# vim: sw=4
diff --git a/tools/mkrelease.sh b/tools/mkrelease.sh
new file mode 100755
index 000000000000..66b10348a7b9
--- /dev/null
+++ b/tools/mkrelease.sh
@@ -0,0 +1,317 @@
+#!/usr/bin/env bash
+
+set -eo pipefail
+# set -x
+
+declare -r USAGE="
+USAGE:
+    $0 [OPTIONS] [--] ARCHIVE_NAME|DIRECTORY/ [PATTERNS]
+
+OPTIONS:
+    -j N, --jobs N               use up to N processes / threads
+    -e EPOCH, --epoch EPOCH      set contents timestamp to EPOCH
+    -m ENTRY, --manifest ENTRY   add a manifest ENTRY to the release
+    --manifest-transform SCRIPT  transform manifest using sed SCRIPT
+    -o OPTS, --options OPTS      forward options to compressor
+"
+
+# shellcheck disable=SC2016
+declare -r AWK_HELPERS='
+function print_entry(path, size, crc) {
+    sub("/$", "", path)
+    if (crc)
+        print path, size, crc
+    else
+        print path"/"
+}
+function reverse_entry() {
+    $0 = $3" "$2" "$1;
+}
+'
+
+if [[ "${OSTYPE}" = darwin* ]]; then
+    declare -r READLINK=greadlink
+    declare -r TAR=gtar
+else
+    declare -r READLINK=readlink
+    declare -r TAR=tar
+fi
+
+if ! opt=$(getopt -o '+de:hj:m:o:' --long 'debug,epoch:,help,jobs:,manifest:,manifest-transform:,options:' --name "$0" -- "$@"); then
+    echo "${USAGE}"
+    exit 1
+fi
+
+# Arguments parsing. {{{
+
+debug=''
+epoch=''
+jobs=''
+manifest=''
+manifest_transform=''
+options=()
+
+eval set -- "${opt}"
+while [[ $# -gt 0 ]]; do
+    case "$1" in
+        -d | --debug)
+            debug=1
+            ;;
+        -e | --epoch)
+            epoch="$2"
+            shift
+            ;;
+        -h | --help)
+            echo "${USAGE}"
+            exit 0
+            ;;
+        -j | --jobs)
+            jobs="$2"
+            shift
+            ;;
+        -m | --manifest)
+            manifest="$2"
+            shift
+            ;;
+        --manifest-transform)
+            manifest_transform="$2"
+            shift
+            ;;
+        -o | --options)
+            declare -a "a=($2)"
+            options+=("${a[@]}")
+            shift
+            ;;
+        --)
+            shift
+            break
+            ;;
+    esac
+    shift
+done
+
+if [[ $# -lt 1 ]]; then
+    echo "${USAGE}"
+    exit 1
+fi
+
+case "$1" in
+    */) format='/' ;;
+    *.7z | *.zip) format="${1##*.}" ;;
+    *.tar.gz | *.targz) format=tar.gz ;;
+    *.tar.xz) format=tar.xz ;;
+    *.tar.zstd) format=tar.zstd ;;
+    *)
+        echo "ERROR: unsupported release format: ${1##*.}" 1>&2
+        exit 2
+        ;;
+esac
+output="$("${READLINK}" -f "$1")"
+shift
+patterns=("$@")
+if [[ -n "${manifest}" ]]; then
+    patterns+=("-x!${manifest}")
+fi
+
+# }}}
+
+if command -v pv >/dev/null; then
+    write_to_file() {
+        pv --interval=0.25 --bytes --timer --rate --output="$1"
+    }
+else
+    write_to_file() {
+        dd bs=4096 of="$1"
+    }
+fi
+
+# Ensure a "traditional" sort order.
+export LC_ALL=C
+
+# We need to use the full path to the executable to avoid
+# a weird issue when using the p7zip project pre-built
+# binary (`Can't load './7z.dll' (7z.so)...`).
+if ! sevenzip="$(which 7z)"; then
+    echo "ERROR: 7z executable not found!" 1>&2
+    exit 2
+fi
+sevenzip_compress_cmd=("${sevenzip}")
+
+# Setup temporary directory.
+tmpdir="$(mktemp -d -t tmp7z.XXXXXXXXXX)"
+trap 'rm -rf "${tmpdir}"' EXIT
+mkdir -p "${tmpdir}/contents"
+
+# Detect if that version of 7z deferences symlinks by default.
+sevenzip_manifest_cmd=("${sevenzip}" -ba h)
+ln -s /dev/null "${tmpdir}/symlink"
+checksum="$("${sevenzip_manifest_cmd[@]}" "${tmpdir}/symlink" | awk '{ print $1 }')"
+if [[ "${checksum}" != '00000000' ]]; then
+    sevenzip_manifest_cmd+=(-l)
+fi
+rm -f "${tmpdir}/symlink"
+
+# Prefer `pigz` over `gzip` (faster).
+gzip="$(command -v pigz || command -v gzip)"
+gzip_cmd=("${gzip}")
+
+# Jobs.
+if [[ -n "${jobs}" ]]; then
+    [[ "${gzip}" != */pigz ]] || gzip_cmd+=(--processes "${jobs}")
+    sevenzip_compress_cmd+=(-mmt="${jobs}")
+fi
+
+# In-place sed command.
+if [[ "${OSTYPE}" = darwin* ]]; then
+    ised=(sed -i '' -e)
+else
+    ised=(sed -i -e)
+fi
+
+if [[ -n "${debug}" ]]; then
+    echo "format              : ${format}"
+    echo "output              : ${output}"
+    echo "manifest            : ${manifest}"
+    echo "manifest transform  : ${manifest_transform}"
+    echo "epoch               : ${epoch}"
+    echo "options             : ${options[*]@Q}"
+    echo "patterns            : ${patterns[*]@Q}"
+    echo "7z executable       : ${sevenzip}"
+    echo "7z compress command : ${sevenzip_compress_cmd[*]@Q}"
+    echo "7z manifest command : ${sevenzip_manifest_cmd[*]@Q}"
+    echo "gzip executable     : ${gzip}"
+    echo "gzip command        : ${gzip_cmd[*]@Q}"
+    echo "sed in-place command: ${ised[*]@Q}"
+    [[ -t 0 ]] && read -srn 1
+fi
+
+# Build manifest.
+"${sevenzip_manifest_cmd[@]}" "${patterns[@]}" |
+    awk "${AWK_HELPERS}"'{ reverse_entry(); print_entry($1, $2, $3) }' |
+    sort -o "${tmpdir}/manifest"
+
+# Extract list of paths from manifest.
+rev <"${tmpdir}/manifest" | cut -f3- -d' ' | rev >"${tmpdir}/paths"
+# Quick sanity check: no path outside the current directory.
+if grep '^(/|\.\./)' <"${tmpdir}/paths"; then
+    echo "ERROR: ^ some paths are outside the current directory!"
+    exit 2
+fi
+
+# Don't forget the archive's internal manifest, if requested.
+if [[ -n "${manifest}" ]]; then
+    manifest_path=("${manifest}")
+    while [[ "${manifest_path[0]}" = */*[^/] ]]; do
+        manifest_path=("${manifest_path[0]%/*}/" "${manifest_path[@]}")
+    done
+    {
+        cat "${tmpdir}/paths"
+        printf '%s\n' "${manifest_path[@]}"
+    } | sort -u -o "${tmpdir}/paths_with_manifest"
+    install --mode=0644 -D "${tmpdir}/paths_with_manifest" "${tmpdir}/contents/${manifest}"
+    if [[ -n "${manifest_transform}" ]]; then
+        "${ised[@]}" "${manifest_transform}" "${tmpdir}/contents/${manifest}"
+    fi
+    # Can't use 7z's `-w` option in this case…
+    pushd "${tmpdir}/contents" >/dev/null
+    "${sevenzip[@]}" -ba h |
+        awk "${AWK_HELPERS}"'{ reverse_entry(); print_entry($1, $2, $3) }' >>"${tmpdir}/manifest"
+    popd >/dev/null
+    sort -u -o "${tmpdir}/manifest" "${tmpdir}/manifest"
+fi
+
+if [[ -n "${debug}" ]] && [[ -t 0 ]]; then
+    paths=("${tmpdir}/manifest" "${tmpdir}"/paths*)
+    [[ -z "${manifest}" ]] || paths+=("${tmpdir}/contents/${manifest}")
+    less "${paths[@]}"
+fi
+
+# If the output already exists, check for changes.
+if [[ -r "${output}" ]]; then
+    previous_manifest=''
+    case "${format}" in
+        /) ;;
+        tar*) ;;
+        *)
+            previous_manifest="$(
+                "${sevenzip[@]}" -ba -slt l "${output}" |
+                    awk "${AWK_HELPERS}"'
+                        /^[^=]+ = / { e[$1] = $3; }
+                        /^$/ && e["Size"] != "" { print_entry(e["Path"], e["Size"], e["CRC"]) }
+                        ' | sort
+            )"
+            ;;
+    esac
+    if [[ -n "${previous_manifest}" ]] &&
+        diff --color${CLICOLOR_FORCE:+=always} --unified \
+            --label 'old' <(printf '%s\n' "${previous_manifest}") \
+            --label 'new' "${tmpdir}/manifest"; then
+        exit
+    fi
+    # There's no 7z or zip option to overwrite the output
+    # if it already exists (instead of updating it), and
+    # it may be a directory anyway…
+    rm -rf "${output}"
+fi
+
+# Make a copy of everything so we can later patch timestamps and
+# fix permissions to ensure reproducibility.
+# Note: We want to keep "empty" (with ignored files) directories.
+"${TAR}" --create --dereference --hard-dereference --no-recursion \
+    --verbatim-files-from --files-from="${tmpdir}/paths" |
+    "${TAR}" --extract --directory="${tmpdir}/contents"
+
+cd "${tmpdir}/contents"
+
+# Fix permissions.
+chmod -R u=rwX,og=rX .
+
+# Fix timestamps.
+if [[ -n "${epoch}" ]]; then
+    find . -depth -print0 | xargs -0 touch --date="${epoch}"
+fi
+
+# And create the final output.
+if [[ -n "${manifest}" ]]; then
+    filelist="${tmpdir}/paths_with_manifest"
+else
+    filelist="${tmpdir}/paths"
+fi
+sevenzip_compress_cmd+=("${options[@]}" a "${output}" "-i@${filelist}")
+tar_compress_cmd=(
+    "${TAR}" --create --no-recursion --owner=0 --group=0
+    --verbatim-files-from --files-from="${filelist}"
+)
+case "${format}" in
+    /)
+        mv "${tmpdir}/contents" "${output}"
+        ;;
+    7z)
+        # Note: sort by type (for better compression).
+        "${sevenzip_compress_cmd[@]}" -mqs
+        ;;
+    tar.gz)
+        echo "Creating archive: ${output}"
+        # Note: create a rsyncable gzipped tar.
+        "${tar_compress_cmd[@]}" |
+            "${gzip}" --no-name --rsyncable "${options[@]}" --stdout |
+            write_to_file "${output}"
+        ;;
+    tar.xz)
+        echo "Creating archive: ${output}"
+        "${tar_compress_cmd[@]}" |
+            xz ${jobs:+--threads=${jobs}} "${options[@]}" |
+            write_to_file "${output}"
+        ;;
+    tar.zstd)
+        echo "Creating archive: ${output}"
+        "${tar_compress_cmd[@]}" |
+            zstd ${jobs:+--threads=${jobs}} "${options[@]}" --stdout |
+            write_to_file "${output}"
+        ;;
+    zip)
+        "${sevenzip_compress_cmd[@]}" -tzip
+        ;;
+esac
+
+# vim: foldmethod=marker foldlevel=0 sw=4