Add tag name to error messages

Before this change, the error only included the location of the tag.

Closes #26001.

PiperOrigin-RevId: 758564950
Change-Id: I3f51492585b7149401379c373de7225649219cfa

Author: fmeum

src/main/java/com/google/devtools/build/lib/bazel/bzlmod/AttributeValues.java

@@ -62,8 +62,14 @@ public static void validateSingleAttr(
     String repoName = label.getRepository().getName();
     throw Starlark.errorf(
         "no repository visible as '@%s' %s, but referenced by label '@%s//%s:%s' in"
-            + " attribute '%s' of %s.",
-        repoName, where, repoName, label.getPackageName(), label.getName(), attrName, what);
+            + " attribute '%s'%s.",
+        repoName,
+        where,
+        repoName,
+        label.getPackageName(),
+        label.getName(),
+        attrName,
+        what.isEmpty() ? "" : " of " + what);
   }
 
   private static Optional<Label> getFirstNonVisibleLabel(Object nativeAttrValue) {

src/main/java/com/google/devtools/build/lib/bazel/bzlmod/TypeCheckedTag.java

@@ -66,7 +66,8 @@ public static TypeCheckedTag create(
       if (attrIndex == null) {
         throw ExternalDepsException.withMessage(
             Code.BAD_MODULE,
-            "in tag at %s, unknown attribute %s provided%s",
+            "in '%s' tag at %s, unknown attribute %s provided%s",
+            tag.getTagName(),
             tag.getLocation(),
             attrValue.getKey(),
             SpellChecker.didYouMean(attrValue.getKey(), tagClass.attributeIndices().keySet()));
@@ -80,7 +81,8 @@ public static TypeCheckedTag create(
         throw ExternalDepsException.withCauseAndMessage(
             Code.BAD_MODULE,
             e,
-            "in tag at %s, error converting value for attribute %s",
+            "in '%s' tag at %s, error converting value for attribute %s",
+            tag.getTagName(),
             tag.getLocation(),
             attr.getPublicName());
       }
@@ -89,7 +91,8 @@ public static TypeCheckedTag create(
       if (attr.checkAllowedValues() && !attr.getAllowedValues().apply(nativeValue)) {
         throw ExternalDepsException.withMessage(
             Code.BAD_MODULE,
-            "in tag at %s, the value for attribute %s %s",
+            "in '%s' tag at %s, the value for attribute %s %s",
+            tag.getTagName(),
             tag.getLocation(),
             attr.getPublicName(),
             attr.getAllowedValues().getErrorReason(nativeValue));
@@ -105,7 +108,8 @@ public static TypeCheckedTag create(
       if (attr.isMandatory() && attrValues[i] == null) {
         throw ExternalDepsException.withMessage(
             Code.BAD_MODULE,
-            "in tag at %s, mandatory attribute %s isn't being specified",
+            "in '%s' tag at %s, mandatory attribute %s isn't being specified",
+            tag.getTagName(),
             tag.getLocation(),
             attr.getPublicName());
       }
@@ -117,10 +121,14 @@ public static TypeCheckedTag create(
             attr.getPublicName(),
             attrValues[i],
             String.format("to the %s", moduleDisplayString),
-            String.format("tag '%s'", tag.getTagName()));
+            /* what= */ "");
       } catch (EvalException e) {
         throw ExternalDepsException.withMessage(
-            Code.BAD_MODULE, "in tag at %s: %s", tag.getLocation(), e.getMessage());
+            Code.BAD_MODULE,
+            "in '%s' tag at %s: %s",
+            tag.getTagName(),
+            tag.getLocation(),
+            e.getMessage());
       }
     }
     return new TypeCheckedTag(

src/test/java/com/google/devtools/build/lib/bazel/bzlmod/ModuleExtensionResolutionTest.java

@@ -1269,9 +1269,8 @@ public void nonVisibleLabelInLabelAttrForwardedFromTag() throws Exception {
         .hasMessageThat()
         .isEqualTo(
             """
-            in tag at /workspace/MODULE.bazel:2:10: no repository visible as '@other_repo' to the \
-            root module, but referenced by label '@other_repo//:foo' in attribute 'label' of tag \
-            'label'.\
+            in 'label' tag at /workspace/MODULE.bazel:2:10: no repository visible as '@other_repo' \
+            to the root module, but referenced by label '@other_repo//:foo' in attribute 'label'.\
             """);
   }