diff --git a/BuildUtils.pm b/BuildUtils.pm
index 306d7f7cb..b417ef243 100644
--- a/BuildUtils.pm
+++ b/BuildUtils.pm
@@ -22,7 +22,8 @@ our @EXPORT_OK = qw(
     source_date_epoch snap_release deb_version
     stage_probe_helpers XCAT_PROBE_HELPERS
     deb_package_arches dist_arches default_dists
-    orig_tarball_name pin_control_version rewrite_changelog_header
+    orig_tarball_name upstream_version resolve_dest
+    pin_control_version rewrite_changelog_header
     reprepro_distributions reprepro_options
     lock_id_for take_build_lock
     sh_quote
@@ -132,10 +133,37 @@ sub dist_arches {
 }
 
 # orig_tarball_name: the .orig.tar.gz dpkg-source expects for a 3.0 (quilt) package.
-# The name is lower-cased because dpkg requires a lower-case source package name.
+#
+# The name carries the UPSTREAM version only -- dpkg looks for
+# <source>_<upstream>.orig.tar.gz, with no Debian revision, because one upstream
+# tarball is shared by every revision built from it. The revision is stripped here
+# rather than at the call site so passing the full Version-Release cannot produce a
+# tarball dpkg will not find. Lower-cased because dpkg requires a lower-case source
+# package name.
+sub upstream_version {
+    my ($version) = @_;
+    return '' unless defined $version;
+    $version =~ s/-[^-]*\z//;    # drop the Debian revision, if any
+    return $version;
+}
+
 sub orig_tarball_name {
     my ($package, $version) = @_;
-    return lc($package) . "_$version.orig.tar.gz";
+    return lc($package) . '_' . upstream_version($version) . '.orig.tar.gz';
+}
+
+# resolve_dest: turn a --dest argument into an absolute path.
+#
+# NOT Cwd::abs_path: that returns undef when a PARENT component is missing, and the
+# caller then interpolates undef, so `--dest /no/such/parent/out` silently becomes
+# `/debs` and `/xcat-core` at the filesystem root. rel2abs is purely lexical and
+# works for a path that does not exist yet, which is the normal case for an output
+# directory.
+sub resolve_dest {
+    my ($dest, $default) = @_;
+    return $default unless defined $dest && length $dest;
+    require File::Spec;
+    return File::Spec->rel2abs($dest);
 }
 
 # pin_control_version: pin xCAT's inter-package dependencies to this exact build.
diff --git a/Gitinfo b/Gitinfo
new file mode 100644
index 000000000..8c55c71c5
--- /dev/null
+++ b/Gitinfo
@@ -0,0 +1 @@
+5515dfbe3e5ac3a305a60422def89f12e6318ce8
diff --git a/builddebs.pl b/builddebs.pl
index 915c792b9..d7214f015 100755
--- a/builddebs.pl
+++ b/builddebs.pl
@@ -31,7 +31,8 @@ use BuildUtils qw(
     source_date_epoch snap_release deb_version
     stage_probe_helpers XCAT_PROBE_HELPERS
     deb_package_arches dist_arches default_dists
-    orig_tarball_name pin_control_version rewrite_changelog_header
+    orig_tarball_name upstream_version resolve_dest
+    pin_control_version rewrite_changelog_header
     reprepro_distributions reprepro_options
     lock_id_for take_build_lock sh_quote
 );
@@ -135,17 +136,29 @@ sub with_prepared_tree {
     my $dir = "$ROOT/$pkg";
     my @restore;
 
-    my $save = sub {
+    my @remove;
+
+    # Back up a file the build is about to edit, or -- when it does not exist yet --
+    # note that the build is CREATING it so it can be taken away again.
+    # xCAT-genesis-scripts has no debian/control of its own; it is generated from
+    # control-<arch>. Restoring only pre-existing files left that generated file in
+    # the checkout, so the tree ended dirty and a later single-arch build would start
+    # from the other architecture's control.
+    my $claim = sub {
         my ($rel) = @_;
         my $path = "$dir/$rel";
-        return unless -f $path;
-        my $backup = "$path.build.save";
-        copy($path, $backup) or die "Cannot back up $path: $!\n";
-        push @restore, [$backup, $path];
+        if (-f $path) {
+            my $backup = "$path.build.save";
+            copy($path, $backup) or die "Cannot back up $path: $!\n";
+            push @restore, [$backup, $path];
+        }
+        else {
+            push @remove, $path;
+        }
     };
 
-    $save->('debian/control');
-    $save->('debian/changelog');
+    $claim->('debian/control');
+    $claim->('debian/changelog');
 
     # Pin the intra-xCAT dependencies to this exact build, so a partial upgrade cannot
     # mix versions.
@@ -200,7 +213,7 @@ sub with_prepared_tree {
     my $rc = eval { $body->($dir); 1 } ? 0 : 1;
     my $err = $@;
 
-    unlink @added;
+    unlink @added, @remove;
     for my $pair (reverse @restore) {
         my ($backup, $path) = @$pair;
         move($backup, $path) or warn "Could not restore $path: $!\n";
@@ -340,7 +353,7 @@ SCRIPT
 # ----------------------------------------------------------------- main ------
 my $lock = take_build_lock($ROOT);
 
-my $dest   = $opts{dest} ? abs_path($opts{dest}) : "$ROOT/dist/debs";
+my $dest   = resolve_dest($opts{dest}, "$ROOT/dist/debs");
 my $pkgdir = "$dest/debs";
 my $repo   = "$dest/xcat-core";
 make_path($pkgdir);
diff --git a/github_action_xcat_test.pl b/github_action_xcat_test.pl
index e9ca2e5d7..f4480771b 100644
--- a/github_action_xcat_test.pl
+++ b/github_action_xcat_test.pl
@@ -351,7 +351,15 @@ sub build_xcat_core{
 #--------------------------------------------------------
 sub install_xcat{
 
-    my @cmds = ("sudo ./mklocalrepo.sh",
+    my $repo = "$srcdir/dist/debs/xcat-core";
+    unless (-x "$repo/mklocalrepo.sh") {
+        print RED "[install_xcat] $repo/mklocalrepo.sh missing -- did the build run?\n";
+        $check_result_str .= "> **INSTALL XCAT ERROR** : the build produced no apt repository ";
+        print $check_result_str;
+        return 1;
+    }
+
+    my @cmds = ("sudo $repo/mklocalrepo.sh",
                "sudo chmod 777 /etc/apt/sources.list",
                "sudo echo \"deb [arch=amd64 allow-insecure=yes] http://xcat.org/files/xcat/repos/apt/latest/xcat-dep noble main\" >> /etc/apt/sources.list",
                "sudo echo \"deb [arch=ppc64el allow-insecure=yes] http://xcat.org/files/xcat/repos/apt/latest/xcat-dep noble main\" >> /etc/apt/sources.list",
diff --git a/xCAT-test/unit/build_utils.t b/xCAT-test/unit/build_utils.t
index 199872a68..12b118ddc 100644
--- a/xCAT-test/unit/build_utils.t
+++ b/xCAT-test/unit/build_utils.t
@@ -22,7 +22,8 @@ use BuildUtils qw(
     source_date_epoch snap_release deb_version
     stage_probe_helpers XCAT_PROBE_HELPERS
     deb_package_arches dist_arches
-    orig_tarball_name pin_control_version rewrite_changelog_header
+    orig_tarball_name upstream_version resolve_dest
+    pin_control_version rewrite_changelog_header
     reprepro_distributions reprepro_options sh_quote
 );
 
@@ -70,9 +71,29 @@ is_deeply( [dist_arches('noble')], ['amd64', 'ppc64el'],
 is_deeply( [dist_arches('saucy')], ['amd64'],
     'saucy predates ppc64el and serves only amd64' );
 
-is( orig_tarball_name('xCAT-server', '2.19.0-snap1'),
-    'xcat-server_2.19.0-snap1.orig.tar.gz',
-    'the orig tarball name is lower-cased, as dpkg requires' );
+# dpkg looks for <source>_<upstream>.orig.tar.gz -- no Debian revision, because one
+# upstream tarball is shared by every revision built from it.
+is( orig_tarball_name('xCAT-server', '2.19.0-snap202608240826'),
+    'xcat-server_2.19.0.orig.tar.gz',
+    'the orig tarball carries the upstream version, not the Debian revision' );
+is( orig_tarball_name('xCAT-server', '2.19.0'),
+    'xcat-server_2.19.0.orig.tar.gz',
+    'and is the same name when handed the upstream version directly' );
+is( upstream_version('2.19.0-snap1'), '2.19.0', 'the Debian revision is stripped' );
+is( upstream_version('2.19.0'), '2.19.0', 'a bare upstream version is unchanged' );
+is( upstream_version('1.2.3-4-5'), '1.2.3-4', 'only the LAST hyphen separates the revision' );
+is( upstream_version(undef), '', 'an undefined version does not blow up' );
+
+# resolve_dest must not use Cwd::abs_path: that returns undef when a PARENT component
+# is missing, and the caller then builds "/debs" and "/xcat-core" at the root.
+is( resolve_dest(undef, '/default/out'), '/default/out',
+    'no --dest falls back to the default' );
+is( resolve_dest('', '/default/out'), '/default/out',
+    'an empty --dest falls back too' );
+is( resolve_dest('/no-such-parent-xyz/out', '/default'), '/no-such-parent-xyz/out',
+    'a --dest whose parent does not exist resolves to itself, never undef' );
+like( resolve_dest('relative/out', '/default'), qr{^/.*relative/out$},
+    'a relative --dest becomes absolute' );
 
 # ------------------------------------------------------------------- control --