BackupPC is incompatible with perl's Data::Dumper since 2.182; Arch ships 2.184 currently. Worst case, BackupPC server instances would silently terminate without the user/admin noticing. (Flagging as severity high due to potential data loss.)

A patch is available upstream (but not yet in any numbered release): https://github.com/backuppc/backuppc/commit/2c9270b9b849b2c86ae6301dd722c97757bc9256.patch

Upstream bug report: https://github.com/backuppc/backuppc/issues/466
Red Hat bug report: https://bugzilla.redhat.com/show_bug.cgi?id=2091514

Diff for a PKGBUILD including the fix:

diff --git a/trunk/PKGBUILD b/trunk/PKGBUILD
index 8fc33dd..554596b 100644
--- a/trunk/PKGBUILD
+++ b/trunk/PKGBUILD
@@ -4,7 +4,7 @@ pkgname=backuppc
pkgver=4.4.0
_xsver=0.62
_rbpcver=3.1.3.0
-pkgrel=5
+pkgrel=6
pkgdesc='Enterprise-grade system for backing up Linux, Windows and MacOS PCs'
url='https://github.com/backuppc/'
license=('GPL2')
@@ -20,6 +20,7 @@ optdepends=('openssh: ssh transfert support'
source=("https://github.com/backuppc/backuppc/releases/download/$pkgver/BackupPC-$pkgver.tar.gz"
"https://github.com/backuppc/backuppc-xs/releases/download/${_xsver}/BackupPC-XS-${_xsver}.tar.gz"
"https://github.com/backuppc/rsync-bpc/releases/download/${_rbpcver}/rsync-bpc-${_rbpcver}.tar.gz"
+ "https://github.com/backuppc/backuppc/commit/2c9270b9b849b2c86ae6301dd722c97757bc9256.patch"
"$pkgname.service"
"$pkgname.sysusers"
"$pkgname.tmpfiles"
@@ -34,6 +35,7 @@ backup=("etc/$pkgname/config.pl"
sha256sums=('8bc04cd513d47629508bd2fd6f455ced38316974913638e971f44e37786c6365'
'94d863083a466558f82f10b1b95db7742ea99ebce808214f20897b343dc32b18'
'3eeb137319b608512b2d23c54ea8b52b511db806ffbd5fa730a394431d556f3f'
+ 'b4547f90f903d067fd09c4f2c168e204d818b69543defa8cad5dbdd2dfc258eb'
'70b414d681b47b8b41a228d8155761eac5f67b63bcdc6e0e4da7a0d27f3b6810'
'82598186b24b28d7e76c174ac90b046831954d3ebfe22219fa67a9011e306f3f'
'ef5c4fde24e14ab5828fed085a7dd8fd699dfdbbd875bc6c29b41ec2b0ae645b'