diff -Nru apt-cacher-1.7.24/apt-cacher apt-cacher-1.7.25/apt-cacher
--- apt-cacher-1.7.24/apt-cacher	2021-12-21 17:37:19.000000000 +0000
+++ apt-cacher-1.7.25/apt-cacher	2022-01-16 16:10:47.000000000 +0000
@@ -1640,28 +1640,33 @@
 
 sub cache_size {
     use File::Find qw();
-    use IPC::Shareable qw();
+    use IPC::ShareLite qw();
     use IPC::SysV qw();
 
-    tie my %du, 'IPC::Shareable', { key => IPC::SysV::ftok($cfg->{'cache_dir'}, 1),
-				    mode => oct(600),
-				    create => 1} || info_message("Warning: failed to tie hash: $1");
+    my $shm = IPC::ShareLite->new(
+				  -key => IPC::SysV::ftok($cfg->{'cache_dir'}, 2),
+				  -mode => oct(600),
+				  -create => 1,
+				  -destroy => 0
+				 ) or die $!;
+
+    my ($total, $ts) = (0,0);
+    my $cached = $shm->fetch();
+    ($total, $ts) = split('@', $cached) if $cached =~ m/^\d+@\d+$/;
 
     # Sliding scale from 0 to 20 seconds
-    if (($du{'last_time'}||0)  +
-	(20 * ($cfg->{'_disk_usage_limit'} - ($du{'size'}||0)) / $cfg->{'_disk_usage_limit'}) <
-	(my $time = time) and
-	(tied %du)->shlock(LOCK_EX|LOCK_NB)) {
-	$du{'size'}=0;
+    if (($ts + (20 * ($cfg->{'_disk_usage_limit'} - $total) / $cfg->{'_disk_usage_limit'})) < ($ts = time) and
+	$shm->lock(LOCK_EX | LOCK_NB)) {
+	$total = 0;
 	File::Find::find({
-			  wanted => sub { $du{'size'} += -f $_ ? -s _ : 0 },
+			  wanted => sub { $total += -f $_ ? -s _ : 0 },
 			  preprocess => sub { grep {-r}  @_ } # skip non-readable
-		     }, $cfg->{'cache_dir'});
-	$du{'last_time'} = $time;
-	(tied %du)->shunlock;
-	debug_message("Cache Size: $du{'size'}");
+			 }, $cfg->{'cache_dir'});
+	debug_message("Cache Size: $total");
+	$shm->store(join('@', $total, $ts));
+	$shm->lock(LOCK_UN)
     }
-    return $du{'size'};
+    return $total;
 }
 
 sub loadavg {
diff -Nru apt-cacher-1.7.24/debian/changelog apt-cacher-1.7.25/debian/changelog
--- apt-cacher-1.7.24/debian/changelog	2021-12-21 17:37:19.000000000 +0000
+++ apt-cacher-1.7.25/debian/changelog	2022-01-16 16:10:47.000000000 +0000
@@ -1,3 +1,9 @@
+apt-cacher (1.7.25) unstable; urgency=medium
+
+  * Change to use IPC::ShareLite.
+
+ -- Mark Hindley <mark@hindley.org.uk>  Sun, 16 Jan 2022 16:10:47 +0000
+
 apt-cacher (1.7.24) unstable; urgency=medium
 
   [ Debian Janitor ]
diff -Nru apt-cacher-1.7.24/debian/control apt-cacher-1.7.25/debian/control
--- apt-cacher-1.7.24/debian/control	2021-12-21 17:37:19.000000000 +0000
+++ apt-cacher-1.7.25/debian/control	2022-01-16 16:10:47.000000000 +0000
@@ -12,7 +12,7 @@
 Package: apt-cacher
 Architecture: all
 Pre-Depends: ${misc:Pre-Depends}
-Depends: ${perl:Depends}, ${misc:Depends}, libwww-curl-perl, libwww-perl, ed, libio-interface-perl, libio-interactive-perl, libfilesys-df-perl, libnetaddr-ip-perl, lsb-base (>= 3.2-14), update-inetd, libsys-syscall-perl, libipc-shareable-perl, libdpkg-perl
+Depends: ${perl:Depends}, ${misc:Depends}, libwww-curl-perl, libwww-perl, ed, libio-interface-perl, libio-interactive-perl, libfilesys-df-perl, libnetaddr-ip-perl, lsb-base (>= 3.2-14), update-inetd, libsys-syscall-perl, libipc-sharelite-perl, libdpkg-perl
 Recommends: libberkeleydb-perl, libio-compress-lzma-perl
 Suggests: libio-socket-inet6-perl,  libfreezethaw-perl
 Description: Caching proxy server for Debian/Ubuntu/Devuan software repositories