diff --git a/src/main/java/hudson/plugins/mercurial/MercurialSCMSource.java b/src/main/java/hudson/plugins/mercurial/MercurialSCMSource.java
index 21da4022..1dfc8276 100644
--- a/src/main/java/hudson/plugins/mercurial/MercurialSCMSource.java
+++ b/src/main/java/hudson/plugins/mercurial/MercurialSCMSource.java
@@ -7,6 +7,7 @@
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import hudson.AbortException;
 import hudson.EnvVars;
 import hudson.Extension;
 import hudson.FilePath;
@@ -195,13 +196,11 @@ public void setCredentialsId(@CheckForNull String credentialsId) {
                 .newRequest(this, listener) ) {
             MercurialInstallation inst = MercurialSCM.findInstallation(request.installation());
             if (inst == null) {
-                listener.error("No configured Mercurial installation");
-                return;
+                throw new AbortException("No configured Mercurial installation");
             }
             if (!inst.isUseCaches()) {
                 // TODO https://stackoverflow.com/a/11900786/12916 suggests that it may be possible to use a noncaching installation
-                listener.error("Mercurial installation " + request.installation() + " does not support caches");
-                return;
+                throw new AbortException("Mercurial installation " + request.installation() + " does not support caches");
             }
             final Node node = Jenkins.getInstance();
             Launcher launcher = node.createLauncher(listener);
@@ -209,8 +208,7 @@ public void setCredentialsId(@CheckForNull String credentialsId) {
             final FilePath cache = Cache.fromURL(request.source(), credentials, inst.getMasterCacheRoot())
                     .repositoryCache(inst, node, launcher, listener, true);
             if (cache == null) {
-                listener.error("Could not use caches, not fetching branch heads");
-                return;
+                throw new AbortException("Could not use caches, not fetching branch heads");
             }
             try (HgExe hg = new HgExe(inst, credentials, launcher, node, listener, new EnvVars())) {
                 String heads = hg.popen(cache, listener, true,
@@ -266,12 +264,10 @@ protected SCMRevision retrieve(@NonNull String thingName, @NonNull TaskListener
                 .newRequest(this, listener)) {
             MercurialInstallation inst = MercurialSCM.findInstallation(request.installation());
             if (inst == null) {
-                listener.error("No configured Mercurial installation");
-                return null;
+                throw new AbortException("No configured Mercurial installation");
             }
             if (!inst.isUseCaches()) {
-                listener.error("Mercurial installation " + request.installation() + " does not support caches");
-                return null;
+                throw new AbortException("Mercurial installation " + request.installation() + " does not support caches");
             }
             final Node node = Jenkins.getInstance();
             Launcher launcher = node.createLauncher(listener);
@@ -279,8 +275,7 @@ protected SCMRevision retrieve(@NonNull String thingName, @NonNull TaskListener
             final FilePath cache = Cache.fromURL(source, credentials, inst.getMasterCacheRoot())
                     .repositoryCache(inst, node, launcher, listener, true);
             if (cache == null) {
-                listener.error("Could not use caches, not fetching branch heads");
-                return null;
+                throw new AbortException("Could not use caches, not fetching branch heads");
             }
             try (HgExe hg = new HgExe(inst, credentials, launcher, node, listener, new EnvVars())) {
                 String revision = hg.popen(cache, listener, true,
diff --git a/src/test/java/hudson/plugins/mercurial/MercurialSCMSource2Test.java b/src/test/java/hudson/plugins/mercurial/MercurialSCMSource2Test.java
index 5058f5db..b4bb6ea4 100644
--- a/src/test/java/hudson/plugins/mercurial/MercurialSCMSource2Test.java
+++ b/src/test/java/hudson/plugins/mercurial/MercurialSCMSource2Test.java
@@ -61,7 +61,7 @@ public class MercurialSCMSource2Test {
     @ClassRule public static DockerClassRule<MercurialContainer> docker = new DockerClassRule<>(MercurialContainer.class);
     @Rule public TemporaryFolder tmp = new TemporaryFolder();
 
-    @Issue("JENKINS-42278")
+    @Issue({"JENKINS-42278", "JENKINS-48867"})
     @Test public void withCredentialsId() throws Exception {
         m.hg("version"); // test environment needs to be able to run Mercurial
         MercurialContainer container = docker.create();
@@ -97,6 +97,9 @@ public class MercurialSCMSource2Test {
         WorkflowRun b = p.getLastBuild();
         assertNotNull(b);
         r.assertBuildStatusSuccess(b);
+        // JENKINS-48867: if indexing fails, should not lose existing branches
+        sampleRepo.deleteRecursive();
+        assertEquals(p, PipelineTest.scheduleAndFindBranchProject(mp, "default"));
     }
 
 }