diff --git a/t/genesis_openembedded_consumer.t b/t/genesis_openembedded_consumer.t
index d04febf..7c336e4 100644
--- a/t/genesis_openembedded_consumer.t
+++ b/t/genesis_openembedded_consumer.t
@@ -14,6 +14,8 @@ use XCAT::GenesisReleaseTest qw(
   command_exists
   file_sha
   make_export
+  read_file
+  run_capture
   write_checksums
   write_file
   write_release_manifest
@@ -214,21 +216,6 @@ sub make_package_release {
     return $release_root;
 }
 
-sub run_capture {
-    my ($log, @command) = @_;
-    my $pid = fork();
-    die "Cannot fork: $!\n" unless defined $pid;
-    if ($pid == 0) {
-        open(STDOUT, '>:raw', $log) or die $!;
-        open(STDERR, '>&', STDOUT) or die $!;
-        exec(@command) or die "Cannot run $command[0]: $!\n";
-    }
-    waitpid($pid, 0);
-    return 255 if $? == -1;
-    return 128 + ($? & 127) if $? & 127;
-    return $? >> 8;
-}
-
 sub capture {
     my (@command) = @_;
     open(my $fh, '-|', @command) or die $!;
@@ -237,12 +224,3 @@ sub capture {
     chomp($output);
     return $output;
 }
-
-sub read_file {
-    my ($path) = @_;
-    open(my $fh, '<:raw', $path) or die $!;
-    local $/;
-    my $content = <$fh> // '';
-    close($fh) or die $!;
-    return $content;
-}
diff --git a/t/genesis_openembedded_release.t b/t/genesis_openembedded_release.t
index 43266cf..16de0d2 100644
--- a/t/genesis_openembedded_release.t
+++ b/t/genesis_openembedded_release.t
@@ -23,6 +23,8 @@ use XCAT::GenesisReleaseTest qw(
   dies_like
   file_sha
   make_export
+  read_file
+  run_capture
   write_checksums
   write_file
   write_release_manifest
@@ -30,6 +32,7 @@ use XCAT::GenesisReleaseTest qw(
 
 my $repo_root = abs_path("$FindBin::Bin/..");
 my $packager = "$repo_root/genesis-openembedded/package";
+my $builder = "$repo_root/genesis-openembedded/build";
 my $verifier = "$repo_root/genesis-openembedded/verify-release";
 my $revision = 'a' x 40;
 my $version = '2.19.0';
@@ -112,6 +115,36 @@ write_checksums($missing_release);
 dies_like(sub { validate_release($missing_release) }, qr/Genesis release is missing/,
     'incomplete architecture set fails');
 
+SKIP: {
+    skip 'git is not installed', 2 unless command_exists('git');
+    my $source = "$tmp/dirty-xcat-core";
+    make_path("$source/xCAT-genesis-builder/oe");
+    write_file("$source/Version", "$version\n");
+    write_file("$source/xCAT-genesis-builder/oe/build", "#!/bin/sh\nexit 99\n");
+    write_file("$source/xCAT-genesis-builder/oe/export", "#!/bin/sh\nexit 99\n");
+    for my $command (
+        [ 'git', '-C', $source, 'init', '-q' ],
+        [ 'git', '-C', $source, 'add', '.' ],
+        [ 'git', '-C', $source, '-c', 'user.name=xCAT test',
+          '-c', 'user.email=xcat-test@example.invalid', 'commit', '-qm', 'fixture' ],
+    ) {
+        die "Cannot prepare test repository\n"
+          if run_capture("$tmp/git-fixture.log", @{$command});
+    }
+    write_file("$source/untracked", "not part of the commit\n");
+    my $log = "$tmp/dirty-source.log";
+    isnt(
+        run_capture(
+            $log, $builder, '--xcat-source', $source,
+            '--output-dir', "$tmp/dirty-output",
+        ),
+        0,
+        'release builder rejects untracked source files',
+    );
+    like(read_file($log), qr/xcat-core checkout is not clean/,
+        'dirty checkout failure is explicit');
+}
+
 SKIP: {
     skip 'rpmbuild and rpm are not installed', 8
       unless command_exists('rpmbuild') && command_exists('rpm');
diff --git a/t/lib/XCAT/GenesisReleaseTest.pm b/t/lib/XCAT/GenesisReleaseTest.pm
index 0ab3359..a4f83ee 100644
--- a/t/lib/XCAT/GenesisReleaseTest.pm
+++ b/t/lib/XCAT/GenesisReleaseTest.pm
@@ -18,6 +18,8 @@ our @EXPORT_OK = qw(
   dies_like
   file_sha
   make_export
+  read_file
+  run_capture
   write_checksums
   write_file
   write_release_manifest
@@ -123,6 +125,30 @@ sub command_exists {
     return 0;
 }
 
+sub run_capture {
+    my ($log, @command) = @_;
+    my $pid = fork();
+    die "Cannot fork: $!\n" unless defined $pid;
+    if ($pid == 0) {
+        open(STDOUT, '>:raw', $log) or die $!;
+        open(STDERR, '>&', STDOUT) or die $!;
+        exec(@command) or die "Cannot run $command[0]: $!\n";
+    }
+    waitpid($pid, 0);
+    return 255 if $? == -1;
+    return 128 + ($? & 127) if $? & 127;
+    return $? >> 8;
+}
+
+sub read_file {
+    my ($path) = @_;
+    open(my $fh, '<:raw', $path) or die $!;
+    local $/;
+    my $content = <$fh> // '';
+    close($fh) or die $!;
+    return $content;
+}
+
 sub dies_like {
     my ($code, $pattern, $name) = @_;
     my $error = '';