diff --git a/src/main/java/com/google/devtools/build/lib/cmdline/RepositoryName.java b/src/main/java/com/google/devtools/build/lib/cmdline/RepositoryName.java
index 174f8767fb7b78..b1e6b52a09eba9 100644
--- a/src/main/java/com/google/devtools/build/lib/cmdline/RepositoryName.java
+++ b/src/main/java/com/google/devtools/build/lib/cmdline/RepositoryName.java
@@ -199,13 +199,17 @@ public RepositoryName getOwnerRepoIfNotVisible() {
     return ownerRepoIfNotVisible;
   }
 
-  /** Returns if this is the main repository, that is, {@link #getName} is empty. */
+  /** Returns if this is the main repository. */
   public boolean isMain() {
-    return name.isEmpty();
+    return equals(MAIN);
   }
 
   /** Returns the repository name, with leading "{@literal @}". */
   public String getNameWithAt() {
+    if (!isVisible()) {
+      return String.format(
+          "@[unknown repo '%s' requested from %s]", name, ownerRepoIfNotVisible.getNameWithAt());
+    }
     return '@' + name;
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/cmdline/TargetPattern.java b/src/main/java/com/google/devtools/build/lib/cmdline/TargetPattern.java
index 986f172a58b1c9..93edaa1d603b25 100644
--- a/src/main/java/com/google/devtools/build/lib/cmdline/TargetPattern.java
+++ b/src/main/java/com/google/devtools/build/lib/cmdline/TargetPattern.java
@@ -921,8 +921,8 @@ public TargetPattern parse(String pattern) throws TargetParsingException {
         if (!repository.isVisible()) {
           throw new TargetParsingException(
               String.format(
-                  "Repository '%s' is not visible from repository '@%s'",
-                  repository.getNameWithAt(), repository.getOwnerRepoIfNotVisible()),
+                  "Repository '@%s' is not visible from repository '@%s'",
+                  repository.getName(), repository.getOwnerRepoIfNotVisible()),
               Code.PACKAGE_NOT_FOUND);
         }
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorFunction.java b/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorFunction.java
index 976e1f3cdb6c60..77a52d36833f73 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorFunction.java
@@ -245,9 +245,8 @@ public SkyValue compute(SkyKey skyKey, Environment env)
     if (!repositoryName.isVisible()) {
       return new NoRepositoryDirectoryValue(
           String.format(
-              "Repository '%s' is not visible from repository '%s'",
-              repositoryName.getNameWithAt(),
-              repositoryName.getOwnerRepoIfNotVisible().getNameWithAt()));
+              "Repository '@%s' is not visible from repository '%s'",
+              repositoryName.getName(), repositoryName.getOwnerRepoIfNotVisible().getNameWithAt()));
     }
 
     Map<RepositoryName, PathFragment> overrides = REPOSITORY_OVERRIDES.get(env);
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/PackageLookupFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/PackageLookupFunction.java
index 79d88166e77269..3338d330d60f68 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/PackageLookupFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/PackageLookupFunction.java
@@ -102,8 +102,8 @@ public SkyValue compute(SkyKey skyKey, Environment env)
       return new PackageLookupValue.NoRepositoryPackageLookupValue(
           repoName.getNameWithAt(),
           String.format(
-              "Repository '%s' is not visible from repository '%s'",
-              repoName.getNameWithAt(), repoName.getOwnerRepoIfNotVisible().getNameWithAt()));
+              "Repository '@%s' is not visible from repository '%s'",
+              repoName.getName(), repoName.getOwnerRepoIfNotVisible().getNameWithAt()));
     }
 
     if (deletedPackages.get().contains(packageKey)) {