Trim the package cache by default, and split it from orphan removal

CleanCache was off, so nothing ever pruned /var/cache/pacman/pkg - 23 GB on the
machine this was found on, with three 3.2 GB copies of one package. Trimming
only drops older versions of installed packages and cached versions of
uninstalled ones, so the cost is downgrade depth, not working software.

flatpak uninstall --unused moves from CleanCache to RemoveOrphans, where it
belongs: unused runtimes are the Flatpak equivalent of orphaned packages, and
removing installed software should not hide behind a flag named for cache
trimming. RemoveOrphans stays off - 'orphaned' only means nothing depends on
it, which is also true of something installed deliberately.

The log now reports what a trim reclaimed, since a real paccache run says
almost nothing and there was otherwise no way to tell it was working.

Makefile

@@ -8,7 +8,7 @@
 # Overridable so a packager can pass the version it is actually building
 # (`make VERSION=$pkgver`). The literal below is the fallback for builds
 # straight from a checkout, and is what a release tag has to carry.
-VERSION      ?= 1.0.6
+VERSION      ?= 1.0.7
 
 PREFIX       ?= /usr
 DESTDIR      ?=

README.md

@@ -55,8 +55,15 @@ business rebuilding somebody's system before being asked.
 | Flatpak | system and per-user installations |
 | AppImages | via [Gear Lever](https://github.com/mijorus/gearlever), if installed |
 
-`-git`/`-devel` AUR packages, cache trimming and orphan removal exist as
-options but are off by default.
+It also trims the pacman package cache after each run (`paccache`, keeping the
+3 most recent versions), because otherwise `/var/cache/pacman/pkg` grows
+forever — tens of gigabytes on a machine with a few large packages. Set
+`KeepOldPackages=1` if disk space matters more than the ability to downgrade.
+
+`-git`/`-devel` AUR packages and orphan removal exist as options but are off by
+default. Orphan removal deletes installed software, and "orphaned" only means
+nothing else depends on it — which is also true of something installed
+deliberately.
 
 ## When it holds back
 

res/config/cachy-auto-update.conf

@@ -66,16 +66,29 @@ AutoResolveConflicts=yes
 IgnorePkg=
 
 # ---------------------------------------------------------------------------
-# Housekeeping - all off by default
+# Housekeeping
 # ---------------------------------------------------------------------------
 
-# Trim the pacman package cache after an update.
-CleanCache=no
+# Trim the pacman package cache after an update: drop the older versions of
+# installed packages, and every cached version of packages that are no longer
+# installed. Nothing that is currently installed is ever touched, so this only
+# costs the ability to downgrade further back than KeepOldPackages.
+# Without it /var/cache/pacman/pkg grows forever - tens of gigabytes on a
+# machine with a few large packages.
+CleanCache=yes
 
-# How many old versions per package to keep when CleanCache is on.
+# How many old versions per package to keep when CleanCache is on. 3 is the
+# Arch default and leaves room to downgrade. Set it to 1 if disk space matters
+# more than that; on a machine with a handful of multi-gigabyte packages the
+# difference is easily ten gigabytes.
 KeepOldPackages=3
 
-# Remove packages that were installed as dependencies and are no longer needed.
+# Remove packages nothing depends on any more: pacman packages that were pulled
+# in as dependencies and are now unreferenced, plus Flatpak runtimes no
+# installed application uses.
+# Off by default, and unlike CleanCache this one deletes installed software:
+# "orphaned" only means no other package requires it, which is also true of
+# something installed deliberately as a dependency of nothing.
 RemoveOrphans=no
 
 # ---------------------------------------------------------------------------

src/lib/config.sh

@@ -96,7 +96,7 @@ cau_config_load() {
 	CFG_APPIMAGE=no;              cau_config_bool UpdateAppImages      yes && CFG_APPIMAGE=yes
 	CFG_DEVEL=no;                 cau_config_bool UpdateDevel          no  && CFG_DEVEL=yes
 	CFG_RESOLVE_CONFLICTS=no;     cau_config_bool AutoResolveConflicts yes && CFG_RESOLVE_CONFLICTS=yes
-	CFG_CLEAN_CACHE=no;           cau_config_bool CleanCache           no  && CFG_CLEAN_CACHE=yes
+	CFG_CLEAN_CACHE=no;           cau_config_bool CleanCache           yes && CFG_CLEAN_CACHE=yes
 	CFG_REMOVE_ORPHANS=no;        cau_config_bool RemoveOrphans        no  && CFG_REMOVE_ORPHANS=yes
 	CFG_NOTIFY_SUCCESS=no;        cau_config_bool NotifyOnSuccess      yes && CFG_NOTIFY_SUCCESS=yes
 	CFG_NOTIFY_ERROR=no;          cau_config_bool NotifyOnError        yes && CFG_NOTIFY_ERROR=yes

src/lib/pkg_flatpak.sh

@@ -63,7 +63,10 @@ cau_flatpak_update() {
 		fi
 	done < <(cau_human_users)
 
-	if [[ $CFG_CLEAN_CACHE == yes ]]; then
+	# Unused runtimes are the Flatpak equivalent of orphaned packages - this is
+	# removal of installed software, not cache trimming, so it belongs behind
+	# RemoveOrphans rather than CleanCache.
+	if [[ $CFG_REMOVE_ORPHANS == yes ]]; then
 		cau_run_logged flatpak uninstall --system --unused --noninteractive --assumeyes || true
 	fi
 

src/lib/pkg_pacman.sh

@@ -254,7 +254,14 @@ cau_pacman_cleanup() {
 	fi
 
 	if [[ $CFG_CLEAN_CACHE == yes ]] && cau_have paccache; then
-		cau_info "Trimming the package cache"
+		# paccache's dry run reports what a real run would reclaim; logging it
+		# first is the only way to tell afterwards whether trimming is doing
+		# anything, since the real run says little.
+		local reclaim
+		reclaim="$( { paccache -d --nocolor -k"$CFG_KEEP_OLD"; paccache -du --nocolor -k0; } 2>&1 \
+			| grep -oE 'disk space saved: [^)]*' | paste -sd', ' -)"
+
+		cau_info "Trimming the package cache (keeping $CFG_KEEP_OLD old version(s))${reclaim:+ - $reclaim}"
 		cau_run_logged paccache -r --nocolor -k"$CFG_KEEP_OLD"  || cau_warn "paccache -r failed"
 		cau_run_logged paccache -ru --nocolor -k0               || cau_warn "paccache -ru failed"
 	fi