diff --git a/src/test/java/com/google/devtools/build/lib/packages/PackageFactoryTest.java b/src/test/java/com/google/devtools/build/lib/packages/PackageFactoryTest.java
index 6feb959..972b2fe 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/PackageFactoryTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/PackageFactoryTest.java
@@ -36,11 +36,6 @@
 import com.google.devtools.build.lib.testutil.TestUtils;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -51,6 +46,9 @@
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
 
 /**
  * Unit tests for {@code PackageFactory}.
@@ -690,9 +688,9 @@
     events.setFailFast(false);
     assertGlobFails(
         "glob(1, exclude=2)",
-        "Method glob(include: sequence of strings, *, exclude: sequence of strings, "
+        "method glob(include: sequence of strings, *, exclude: sequence of strings, "
             + "exclude_directories: int) is not applicable for arguments (int, int, int): "
-            + "'include' is int, but should be sequence");
+            + "'include' is 'int', but should be 'sequence'");
   }
 
   @Test
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkAspectsTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkAspectsTest.java
index dbe7efa..0872174 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkAspectsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkAspectsTest.java
@@ -1366,7 +1366,7 @@
     } catch (TargetParsingException | ViewCreationFailedException expected) {
       // expected.
     }
-    assertContainsEvent("Aspect //test:aspect.bzl%my_aspect added more than once");
+    assertContainsEvent("aspect //test:aspect.bzl%my_aspect added more than once");
   }
 
   @Test
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
index cb94367..3013450 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
@@ -294,16 +294,16 @@
         "str",
         "\t\tstr.index(1)"
             + System.lineSeparator()
-            + "Method string.index(sub: string, start: int, end: int or NoneType) is not "
-            + "applicable for arguments (int, int, NoneType): 'sub' is int, "
-            + "but should be string");
+            + "method string.index(sub: string, start: int, end: int or NoneType) is not "
+            + "applicable for arguments (int, int, NoneType): 'sub' is 'int', "
+            + "but should be 'string'");
   }
 
   @Test
   public void testStackTraceMissingMethod() throws Exception {
     runStackTraceTest(
         "None",
-        "\t\tNone.index(1)" + System.lineSeparator() + "Type NoneType has no function index(int)");
+        "\t\tNone.index(1)" + System.lineSeparator() + "type 'NoneType' has no method index(int)");
   }
 
   protected void runStackTraceTest(String object, String errorMessage) throws Exception {
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
index 69783f2..682d987 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
@@ -245,11 +245,13 @@
 
   @Test
   public void testAttrWithWrongProvidersList() throws Exception {
-    checkErrorContains("Illegal argument: element in 'providers' is of unexpected type."
+    checkErrorContains(
+        "element in 'providers' is of unexpected type."
             + " Should be list of string, but got list with an element of type int.",
         "attr.label_list(allow_files = True,  providers = [['a', 1], ['c']])");
 
-    checkErrorContains("Illegal argument: element in 'providers' is of unexpected type."
+    checkErrorContains(
+        "element in 'providers' is of unexpected type."
             + " Should be list of string, but got string.",
         "attr.label_list(allow_files = True,  providers = [['a', 'b'], 'c'])");
   }
@@ -270,12 +272,11 @@
   @Test
   public void testLabelListWithAspectsError() throws Exception {
     checkErrorContains(
-        "Illegal argument: expected type Aspect for 'aspects' element but got type int instead",
+        "expected type 'Aspect' for 'aspects' element but got type 'int' instead",
         "def _impl(target, ctx):",
         "   pass",
         "my_aspect = aspect(implementation = _impl)",
-        "attr.label_list(aspects = [my_aspect, 123])"
-    );
+        "attr.label_list(aspects = [my_aspect, 123])");
   }
 
   @Test
@@ -392,9 +393,9 @@
   @Test
   public void testAttrDefaultValueBadType() throws Exception {
     checkErrorContains(
-        "Method attr.string(*, default: string, mandatory: bool, values: sequence of strings) "
-            + "is not applicable for arguments (int, bool, list): 'default' is int, "
-            + "but should be string",
+        "method attr.string(*, default: string, mandatory: bool, values: sequence of strings) "
+            + "is not applicable for arguments (int, bool, list): 'default' is 'int', "
+            + "but should be 'string'",
         "attr.string(default = 1)");
   }
 
@@ -469,9 +470,9 @@
   @Test
   public void testLateBoundAttrWorksWithOnlyLabel() throws Exception {
     checkEvalError(
-        "Method attr.string(*, default: string, mandatory: bool, values: sequence of strings) "
-            + "is not applicable for arguments (function, bool, list): 'default' is function, "
-            + "but should be string",
+        "method attr.string(*, default: string, mandatory: bool, values: sequence of strings) "
+            + "is not applicable for arguments (function, bool, list): 'default' is 'function', "
+            + "but should be 'string'",
         "def attr_value(cfg): return 'a'",
         "attr.string(default=attr_value)");
   }
@@ -558,8 +559,7 @@
   public void testRuleBadTypeInAdd() throws Exception {
     registerDummyUserDefinedFunction();
     checkErrorContains(
-        "Illegal argument: "
-            + "expected <String, Descriptor> type for 'attrs' but got <string, string> instead",
+        "expected <String, Descriptor> type for 'attrs' but got <string, string> instead",
         "rule(impl, attrs = {'a1': 'some text'})");
   }
 
@@ -908,8 +908,8 @@
 
   @Test
   public void testGetattrNoAttr() throws Exception {
-    checkErrorContains("Object of type 'struct' has no attribute \"b\"",
-        "s = struct(a='val')", "getattr(s, 'b')");
+    checkErrorContains(
+        "object of type 'struct' has no attribute \"b\"", "s = struct(a='val')", "getattr(s, 'b')");
   }
 
   @Test
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleImplementationFunctionsTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleImplementationFunctionsTest.java
index e22b1f1..3749437 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleImplementationFunctionsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleImplementationFunctionsTest.java
@@ -368,7 +368,7 @@
   public void testCreateSpawnActionBadGenericArg() throws Exception {
     checkErrorContains(
         createRuleContext("//foo:foo"),
-        "Illegal argument: expected type File for 'outputs' element but got type string instead",
+        "expected type 'File' for 'outputs' element but got type 'string' instead",
         "l = ['a', 'b']",
         "ruleContext.action(",
         "  outputs = l,",
@@ -597,8 +597,8 @@
     SkylarkRuleContext ruleContext = createRuleContext("//foo:foo");
     checkErrorContains(
         ruleContext,
-        "Method ctx.file_action(output: File, content: string, executable: bool) is not "
-            + "applicable for arguments (File, int, bool): 'content' is int, but should be string",
+        "method ctx.file_action(output: File, content: string, executable: bool) is not applicable "
+            + "for arguments (File, int, bool): 'content' is 'int', but should be 'string'",
         "ruleContext.file_action(",
         "  output = ruleContext.files.srcs[0],",
         "  content = 1,",
@@ -668,7 +668,7 @@
   @Test
   public void testRunfilesBadListGenericType() throws Exception {
     checkErrorContains(
-        "Illegal argument: expected type File for 'files' element but got type string instead",
+        "expected type 'File' for 'files' element but got type 'string' instead",
         "ruleContext.runfiles(files = ['some string'])");
   }
 
@@ -683,18 +683,16 @@
   @Test
   public void testRunfilesBadMapGenericType() throws Exception {
     checkErrorContains(
-        "Illegal argument: expected type string for 'symlinks' key " + "but got type int instead",
+        "expected type 'string' for 'symlinks' key " + "but got type 'int' instead",
         "ruleContext.runfiles(symlinks = {123: ruleContext.files.srcs[0]})");
     checkErrorContains(
-        "Illegal argument: expected type File for 'symlinks' value " + "but got type int instead",
+        "expected type 'File' for 'symlinks' value " + "but got type 'int' instead",
         "ruleContext.runfiles(symlinks = {'some string': 123})");
     checkErrorContains(
-        "Illegal argument: expected type string for 'root_symlinks' key "
-            + "but got type int instead",
+        "expected type 'string' for 'root_symlinks' key " + "but got type 'int' instead",
         "ruleContext.runfiles(root_symlinks = {123: ruleContext.files.srcs[0]})");
     checkErrorContains(
-        "Illegal argument: expected type File for 'root_symlinks' value "
-            + "but got type int instead",
+        "expected type 'File' for 'root_symlinks' value " + "but got type 'int' instead",
         "ruleContext.runfiles(root_symlinks = {'some string': 123})");
   }
 
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/FunctionTest.java b/src/test/java/com/google/devtools/build/lib/syntax/FunctionTest.java
index 3a571b7..464e81c 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/FunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/FunctionTest.java
@@ -324,14 +324,14 @@
 
   @Test
   public void testKwargsBadKey() throws Exception {
-    checkEvalError("Keywords must be strings, not int",
-        "def func(a, b): return a + b",
-        "func('a', **{3: 1})");
+    checkEvalError(
+        "keywords must be strings, not int", "def func(a, b): return a + b", "func('a', **{3: 1})");
   }
 
   @Test
   public void testKwargsIsNotDict() throws Exception {
-    checkEvalError("Argument after ** must be a dictionary, not int",
+    checkEvalError(
+        "argument after ** must be a dictionary, not int",
         "def func(a, b): return a + b",
         "func('a', **42)");
   }
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java b/src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java
index 5fc8aae..cde97c1 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java
@@ -44,7 +44,7 @@
   public void testMinWithInvalidArgs() throws Exception {
     new SkylarkTest()
         .testIfExactError("type 'int' is not iterable", "min(1)")
-        .testIfExactError("Expected at least one argument", "min([])");
+        .testIfExactError("expected at least one argument", "min([])");
   }
 
   @Test
@@ -100,7 +100,7 @@
   public void testMaxWithInvalidArgs() throws Exception {
     new BothModesTest()
         .testIfExactError("type 'int' is not iterable", "max(1)")
-        .testIfExactError("Expected at least one argument", "max([])");
+        .testIfExactError("expected at least one argument", "max([])");
   }
 
   @Test
@@ -402,8 +402,8 @@
     // only one built-in function.
     new BothModesTest()
         .testIfExactError(
-            "Method string.index(sub: string, start: int, end: int or NoneType) is not applicable "
-                + "for arguments (int, int, NoneType): 'sub' is int, but should be string",
+            "method string.index(sub: string, start: int, end: int or NoneType) is not applicable "
+                + "for arguments (int, int, NoneType): 'sub' is 'int', but should be 'string'",
             "'test'.index(1)");
   }
 
@@ -427,9 +427,9 @@
                 + LINE_SEPARATOR
                 + "\t\t'test'.index(x)"
                 + LINE_SEPARATOR
-                + "Method string.index(sub: string, start: int, end: int or NoneType) "
+                + "method string.index(sub: string, start: int, end: int or NoneType) "
                 + "is not applicable "
-                + "for arguments (int, int, NoneType): 'sub' is int, but should be string",
+                + "for arguments (int, int, NoneType): 'sub' is 'int', but should be 'string'",
             "def foo():",
             "  bar(1)",
             "def bar(x):",
@@ -442,13 +442,13 @@
   public void testBuiltinFunctionErrorMessage() throws Exception {
     new BothModesTest()
         .testIfErrorContains(
-            "Method depset.union(new_elements: Iterable) is not applicable for arguments (string): "
-                + "'new_elements' is string, but should be Iterable",
+            "method depset.union(new_elements: Iterable) is not applicable for arguments (string): "
+                + "'new_elements' is 'string', but should be 'Iterable'",
             "depset([]).union('a')")
         .testIfErrorContains(
-            "Method string.startswith(sub: string, start: int, end: int or NoneType) is not "
-                + "applicable for arguments (int, int, NoneType): 'sub' is int, "
-                + "but should be string",
+            "method string.startswith(sub: string, start: int, end: int or NoneType) is not "
+                + "applicable for arguments (int, int, NoneType): 'sub' is 'int', "
+                + "but should be 'string'",
             "'test'.startswith(1)")
         .testIfErrorContains(
             "expected value of type 'list(object)' for parameter args in dict(), "
@@ -469,7 +469,7 @@
   public void testGetAttrMissingField() throws Exception {
     new SkylarkTest()
         .testIfExactError(
-            "Object of type 'string' has no attribute \"not_there\"",
+            "object of type 'string' has no attribute \"not_there\"",
             "getattr('a string', 'not_there')")
         .testStatement("getattr('a string', 'not_there', 'use this')", "use this")
         .testStatement("getattr('a string', 'not there', None)", Runtime.NONE);
@@ -478,7 +478,7 @@
   @Test
   public void testGetAttrWithMethods() throws Exception {
     String msg =
-        "Object of type 'string' has no attribute \"count\", however, "
+        "object of type 'string' has no attribute \"count\", however, "
             + "a method of that name exists";
     new SkylarkTest()
         .testIfExactError(msg, "getattr('a string', 'count')")
@@ -1032,8 +1032,8 @@
   @Test
   public void testListSlice_WrongType() throws Exception {
     new BothModesTest()
-        .testIfExactError("Slice start must be an integer, not 'a'", "'123'['a'::]")
-        .testIfExactError("Slice end must be an integer, not 'b'", "'123'[:'b':]");
+        .testIfExactError("slice start must be an integer, not 'a'", "'123'['a'::]")
+        .testIfExactError("slice end must be an integer, not 'b'", "'123'[:'b':]");
   }
 
   @Test
@@ -1078,7 +1078,7 @@
 
   @Test
   public void testListSliceStep_InvalidStep() throws Exception {
-    String msg = "Slice step cannot be zero";
+    String msg = "slice step cannot be zero";
     new BothModesTest()
         .testIfExactError(msg, "[1, 2, 3][::0]")
         .testIfExactError(msg, "[1, 2, 3][1::0]")
@@ -1102,7 +1102,7 @@
         .testEval("(1, 2, 3, 4, 5)[3:1:-1]", "(4, 3)")
         .testEval("(1, 2, 3, 4, 5)[::-2]", "(5, 3, 1)")
         .testEval("(1, 2, 3, 4, 5)[::-10]", "(5,)")
-        .testIfExactError("Slice step cannot be zero", "(1, 2, 3)[1::0]");
+        .testIfExactError("slice step cannot be zero", "(1, 2, 3)[1::0]");
   }
 
   @Test
@@ -1141,16 +1141,14 @@
   @Test
   public void testDictionaryKeyNotFound() throws Exception {
     new BothModesTest()
-        .testIfErrorContains("Key \"0\" not found in dictionary", "{}['0']")
-        .testIfErrorContains("Key 0 not found in dictionary", "{'0': 1, 2: 3, 4: 5}[0]");
+        .testIfErrorContains("key \"0\" not found in dictionary", "{}['0']")
+        .testIfErrorContains("key 0 not found in dictionary", "{'0': 1, 2: 3, 4: 5}[0]");
   }
 
   @Test
   public void testListAccessBadIndex() throws Exception {
     new BothModesTest()
-        .testIfErrorContains(
-            "Indices must be integers, not string",
-            "[[1], [2]]['a']");
+        .testIfErrorContains("indices must be integers, not string", "[[1], [2]]['a']");
   }
 
   @Test
@@ -1181,9 +1179,9 @@
   @Test
   public void testStringIndexingOutOfRange() throws Exception {
     new BothModesTest()
-        .testIfErrorContains("Index out of range", "'abcdef'[10]")
-        .testIfErrorContains("Index out of range", "'abcdef'[-11]")
-        .testIfErrorContains("Index out of range", "'abcdef'[42]");
+        .testIfErrorContains("index out of range", "'abcdef'[10]")
+        .testIfErrorContains("index out of range", "'abcdef'[-11]")
+        .testIfErrorContains("index out of range", "'abcdef'[42]");
   }
 
   @Test
@@ -1200,8 +1198,8 @@
   @Test
   public void testStringSlice_WrongType() throws Exception {
     new BothModesTest()
-        .testIfExactError("Slice start must be an integer, not 'a'", "'123'['a'::]")
-        .testIfExactError("Slice end must be an integer, not 'b'", "'123'[:'b':]");
+        .testIfExactError("slice start must be an integer, not 'a'", "'123'['a'::]")
+        .testIfExactError("slice end must be an integer, not 'b'", "'123'[:'b':]");
   }
 
   @Test
@@ -1246,7 +1244,7 @@
 
   @Test
   public void testStringSliceStep_InvalidStep() throws Exception {
-    String msg = "Slice step cannot be zero";
+    String msg = "slice step cannot be zero";
     new BothModesTest()
         .testIfExactError(msg, "'123'[::0]")
         .testIfExactError(msg, "'123'[1::0]")
@@ -1300,13 +1298,11 @@
             "expected value of type 'list(object)' for parameter args in dict(), "
                 + "but got \"a\" (string)",
             "dict('a')")
-        .testIfErrorContains(
-            "Cannot convert dictionary update sequence element #0 to a sequence", "dict(['a'])")
-        .testIfErrorContains(
-            "Cannot convert dictionary update sequence element #0 to a sequence", "dict([('a')])")
+        .testIfErrorContains("cannot convert item #0 to a sequence", "dict(['a'])")
+        .testIfErrorContains("cannot convert item #0 to a sequence", "dict([('a')])")
         .testIfErrorContains("too many (3) positional arguments", "dict((3,4), (3,2), (1,2))")
         .testIfErrorContains(
-            "Sequence #0 has length 3, but exactly two elements are required",
+            "item #0 has length 3, but exactly two elements are required",
             "dict([('a', 'b', 'c')])");
   }
 
@@ -1443,8 +1439,8 @@
     new BothModesTest()
         .testIfErrorContains("insufficient arguments received by union", "depset(['a']).union()")
         .testIfErrorContains(
-            "Method depset.union(new_elements: Iterable) is not applicable for arguments (string): "
-                + "'new_elements' is string, but should be Iterable",
+            "method depset.union(new_elements: Iterable) is not applicable for arguments (string): "
+                + "'new_elements' is 'string', but should be 'Iterable'",
             "depset(['a']).union('b')");
   }
 
@@ -1472,8 +1468,8 @@
         .testStatement("[2, 4, 6].index(4)", 1)
         .testStatement("[2, 4, 6].index(4)", 1)
         .testStatement("[0, 1, [1]].index([1])", 2)
-        .testIfErrorContains("Item \"a\" not found in list", "[1, 2].index('a')")
-        .testIfErrorContains("Item 0 not found in list", "[].index(0)");
+        .testIfErrorContains("item \"a\" not found in list", "[1, 2].index('a')")
+        .testIfErrorContains("item 0 not found in list", "[].index(0)");
   }
 
   @Test
@@ -1493,15 +1489,15 @@
   public void testListIndexOutOfRange() throws Exception {
     new BothModesTest()
         .testIfErrorContains(
-            "Index out of range (index is 3, but sequence has 3 elements)", "[0, 1, 2][3]")
+            "index out of range (index is 3, but sequence has 3 elements)", "[0, 1, 2][3]")
         .testIfErrorContains(
-            "Index out of range (index is -4, but sequence has 3 elements)", "[0, 1, 2][-4]")
+            "index out of range (index is -4, but sequence has 3 elements)", "[0, 1, 2][-4]")
         .testIfErrorContains(
-            "Index out of range (index is -2, but sequence has 1 elements)", "[0][-2]")
+            "index out of range (index is -2, but sequence has 1 elements)", "[0][-2]")
         .testIfErrorContains(
-            "Index out of range (index is 1, but sequence has 1 elements)", "[0][1]")
+            "index out of range (index is 1, but sequence has 1 elements)", "[0][1]")
         .testIfErrorContains(
-            "Index out of range (index is 1, but sequence has 0 elements)", "[][1]");
+            "index out of range (index is 1, but sequence has 0 elements)", "[][1]");
   }
 
   @Test
@@ -1511,8 +1507,8 @@
         .testStatement("hash('skylark')", "skylark".hashCode())
         .testStatement("hash('google')", "google".hashCode())
         .testIfErrorContains(
-            "Method hash(value: string) is not applicable for arguments (NoneType): "
-                + "'value' is NoneType, but should be string",
+            "method hash(value: string) is not applicable for arguments (NoneType): "
+                + "'value' is 'NoneType', but should be 'string'",
             "hash(None)");
   }
 
@@ -1550,8 +1546,8 @@
   public void testEnumerateBadArg() throws Exception {
     new BothModesTest()
         .testIfErrorContains(
-            "Method enumerate(list: sequence) is not applicable for arguments (string): "
-                + "'list' is string, but should be sequence",
+            "method enumerate(list: sequence) is not applicable for arguments (string): "
+                + "'list' is 'string', but should be 'sequence'",
             "enumerate('a')");
   }
 
@@ -1568,7 +1564,7 @@
         .testLookup("FOO", MutableList.of(env, "f", "c", "d", "a", "b", "e"))
         .setUp("FOO.insert(10, 'g')")
         .testLookup("FOO", MutableList.of(env, "f", "c", "d", "a", "b", "e", "g"))
-        .testIfErrorContains("Type tuple has no function insert(int)", "(1, 2).insert(3)");
+        .testIfErrorContains("type 'tuple' has no method insert(int)", "(1, 2).insert(3)");
   }
 
   @Test
@@ -1576,7 +1572,7 @@
     new BuildTest()
         .setUp("FOO = ['a', 'b']", "FOO.append('c')")
         .testLookup("FOO", MutableList.of(env, "a", "b", "c"))
-        .testIfErrorContains("Type tuple has no function append(int)", "(1, 2).append(3)");
+        .testIfErrorContains("type 'tuple' has no method append(int)", "(1, 2).append(3)");
   }
 
   @Test
@@ -1584,10 +1580,10 @@
     new BuildTest()
         .setUp("FOO = ['a', 'b']", "FOO.extend(['c', 'd'])", "FOO.extend(('e', 'f'))")
         .testLookup("FOO", MutableList.of(env, "a", "b", "c", "d", "e", "f"))
-        .testIfErrorContains("Type tuple has no function extend(list)", "(1, 2).extend([3, 4])")
+        .testIfErrorContains("type 'tuple' has no method extend(list)", "(1, 2).extend([3, 4])")
         .testIfErrorContains(
-            "Method list.extend(items: sequence) is not applicable for arguments "
-                + "(int): 'items' is int, but should be sequence",
+            "method list.extend(items: sequence) is not applicable for arguments "
+                + "(int): 'items' is 'int', but should be 'sequence'",
             "[1, 2].extend(3)");
   }
 
@@ -1602,10 +1598,10 @@
         .testLookup("foo", MutableList.of(env, "b"))
         .setUp("foo.remove('b')")
         .testLookup("foo", MutableList.of(env))
-        .testIfErrorContains("Item 3 not found in list", "[1, 2].remove(3)");
+        .testIfErrorContains("item 3 not found in list", "[1, 2].remove(3)");
 
     new BothModesTest()
-        .testIfErrorContains("Type tuple has no function remove(int)", "(1, 2).remove(3)");
+        .testIfErrorContains("type 'tuple' has no method remove(int)", "(1, 2).remove(3)");
   }
 
   @Test
@@ -1624,9 +1620,9 @@
         .testLookup("ret", 3);
     new BothModesTest()
         .testIfErrorContains(
-            "Index out of range (index is 3, but sequence has 2 elements)", "[1, 2].pop(3)");
+            "index out of range (index is 3, but sequence has 2 elements)", "[1, 2].pop(3)");
 
-    new BothModesTest().testIfErrorContains("Type tuple has no function pop()", "(1, 2).pop()");
+    new BothModesTest().testIfErrorContains("type 'tuple' has no method pop()", "(1, 2).pop()");
   }
 
   @Test
@@ -1661,8 +1657,8 @@
   @Test
   public void testIndexOnFunction() throws Exception {
     new BothModesTest()
-        .testIfErrorContains("Type function has no operator [](int)", "len[1]")
-        .testIfErrorContains("Type function has no operator [:](int, int, int)", "len[1:4]");
+        .testIfErrorContains("type 'function' has no operator [](int)", "len[1]")
+        .testIfErrorContains("type 'function' has no operator [:](int, int, int)", "len[1:4]");
   }
 
   @Test
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
index 7a48b20..f6493ba 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
@@ -691,28 +691,28 @@
   public void testJavaCallsNotSkylarkCallable() throws Exception {
     new SkylarkTest()
         .update("mock", new Mock())
-        .testIfExactError("Type Mock has no function value()", "mock.value()");
+        .testIfExactError("type 'Mock' has no method value()", "mock.value()");
   }
 
   @Test
   public void testNoOperatorIndex() throws Exception {
     new SkylarkTest()
         .update("mock", new Mock())
-        .testIfExactError("Type Mock has no operator [](int)", "mock[2]");
+        .testIfExactError("type 'Mock' has no operator [](int)", "mock[2]");
   }
 
   @Test
   public void testJavaCallsNoMethod() throws Exception {
     new SkylarkTest()
         .update("mock", new Mock())
-        .testIfExactError("Type Mock has no function bad()", "mock.bad()");
+        .testIfExactError("type 'Mock' has no method bad()", "mock.bad()");
   }
 
   @Test
   public void testJavaCallsNoMethodErrorMsg() throws Exception {
     new SkylarkTest()
         .testIfExactError(
-            "Type int has no function bad(string, string, string)", "s = 3.bad('a', 'b', 'c')");
+            "type 'int' has no method bad(string, string, string)", "s = 3.bad('a', 'b', 'c')");
   }
 
   @Test
@@ -720,7 +720,7 @@
     new SkylarkTest()
         .update("mock", new MockMultipleMethodClass())
         .testIfExactError(
-            "Type MockMultipleMethodClass has multiple matches for function method(string)",
+            "type 'MockMultipleMethodClass' has multiple matches for function method(string)",
             "s = mock.method('string')");
   }
 
@@ -729,7 +729,7 @@
     new SkylarkTest()
         .update("mock", new Mock())
         .testIfExactError(
-            "Type Mock has no function isEmpty(string str)", "mock.isEmpty(str='abc')");
+            "type 'Mock' has no method isEmpty(string str)", "mock.isEmpty(str='abc')");
   }
 
 
@@ -743,14 +743,14 @@
         .update("mock", new Mock())
         .setUp("")
         .testIfExactError(
-            "Parameter 'named' has no default value (in function with_params(int, bool) of Mock).",
+            "parameter 'named' has no default value, in method with_params(int, bool) of 'Mock'",
             "mock.with_params(1, True)");
     new SkylarkTest()
         .update("mock", new Mock())
         .setUp("")
         .testIfExactError(
-            "Parameter 'named' has no default value (in function with_params(int, bool, bool) "
-                + "of Mock).",
+            "parameter 'named' has no default value, in method with_params(int, bool, bool) "
+                + "of 'Mock'",
             "mock.with_params(1, True, True)");
     new SkylarkTest()
         .update("mock", new Mock())
@@ -768,21 +768,21 @@
         .update("mock", new Mock())
         .setUp("")
         .testIfExactError(
-            "Too many arguments (in function with_params(int, bool, bool named, "
-                + "bool posOrNamed, int n) of Mock).",
+            "too many arguments, in method with_params(int, bool, bool named, "
+                + "bool posOrNamed, int n) of 'Mock'",
             "mock.with_params(1, True, named=True, posOrNamed=True, n=2)");
     new SkylarkTest()
         .update("mock", new Mock())
         .setUp("")
         .testIfExactError(
-            "Parameter 'nonNoneable' cannot be None (in function with_params(int, bool, bool, "
-                + "bool named, bool optionalNamed, NoneType nonNoneable) of Mock).",
+            "parameter 'nonNoneable' cannot be None, in method with_params(int, bool, bool, "
+                + "bool named, bool optionalNamed, NoneType nonNoneable) of 'Mock'",
             "mock.with_params(1, True, True, named=True, optionalNamed=False, nonNoneable=None)");
   }
 
   @Test
   public void testNoJavaCallsWithoutSkylark() throws Exception {
-    new SkylarkTest().testIfExactError("Type int has no function to_string()", "s = 3.to_string()");
+    new SkylarkTest().testIfExactError("type 'int' has no method to_string()", "s = 3.to_string()");
   }
 
   @Test
@@ -790,7 +790,7 @@
     new SkylarkTest()
         .update("mock", new MockSubClass())
         .testIfExactError(
-            "Type Mock has no function is_empty_class_not_annotated(string)",
+            "type 'Mock' has no method is_empty_class_not_annotated(string)",
             "b = mock.is_empty_class_not_annotated('a')");
   }
 
@@ -822,7 +822,7 @@
   public void testStructAccessOfMethod() throws Exception {
     new SkylarkTest()
         .update("mock", new Mock())
-        .testIfExactError("Object of type 'Mock' has no field \"function\"", "v = mock.function");
+        .testIfExactError("object of type 'Mock' has no field \"function\"", "v = mock.function");
   }
 
   @Test
@@ -830,17 +830,16 @@
     new SkylarkTest()
         .update("mock", new Mock())
         .testIfExactError(
-            "Method 'return_bad' returns an object of invalid type Bad",
-            "mock.return_bad()");
+            "method 'return_bad' returns an object of invalid type Bad", "mock.return_bad()");
   }
 
   @Test
   public void testJavaFunctionReturnsNullFails() throws Exception {
     new SkylarkTest()
         .update("mock", new Mock())
-        .testIfExactError(
-            "Method invocation returned None,"
-            + " please contact Skylark developers: nullfunc_failing(\"abc\", 1)",
+        .testIfErrorContains(
+            "method invocation returned None,"
+                + " please file a bug report: nullfunc_failing(\"abc\", 1)",
             "mock.nullfunc_failing('abc', 1)");
   }
 
@@ -872,7 +871,7 @@
   public void testClassObjectCannotAccessNestedSet() throws Exception {
     new SkylarkTest()
         .update("mock", new MockClassObject())
-        .testIfExactError("Type is not allowed in Skylark: NestedSet", "v = mock.nset");
+        .testIfErrorContains("internal error: type 'NestedSet' is not allowed", "v = mock.nset");
   }
 
   @Test
@@ -908,8 +907,9 @@
 
   @Test
   public void testStaticDirectJavaCallMethodIsNonStatic() throws Exception {
-    new SkylarkTest().update("Mock", Mock.class).testIfExactError("Method 'is_empty' is not static",
-        "val = Mock.is_empty('a')");
+    new SkylarkTest()
+        .update("Mock", Mock.class)
+        .testIfExactError("method 'is_empty' is not static", "val = Mock.is_empty('a')");
   }
 
   @Test
@@ -925,8 +925,8 @@
 
   @Test
   public void testDotExpressionOnNonStructObject() throws Exception {
-    new SkylarkTest().testIfExactError("Object of type 'string' has no field \"field\"",
-        "x = 'a'.field");
+    new SkylarkTest()
+        .testIfExactError("object of type 'string' has no field \"field\"", "x = 'a'.field");
   }
 
   @Test
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkListTest.java b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkListTest.java
index d6fa9fd..8a17607 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkListTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkListTest.java
@@ -43,12 +43,11 @@
 
   @Test
   public void testIndexOutOfBounds() throws Exception {
-    checkEvalError("Index out of range (index is 3, but sequence has 3 elements)",
-        "['a', 'b', 'c'][3]");
-    checkEvalError("Index out of range (index is 10, but sequence has 3 elements)",
-        "['a', 'b', 'c'][10]");
-    checkEvalError("Index out of range (index is 0, but sequence has 0 elements)",
-        "[][0]");
+    checkEvalError(
+        "index out of range (index is 3, but sequence has 3 elements)", "['a', 'b', 'c'][3]");
+    checkEvalError(
+        "index out of range (index is 10, but sequence has 3 elements)", "['a', 'b', 'c'][10]");
+    checkEvalError("index out of range (index is 0, but sequence has 0 elements)", "[][0]");
   }
 
   @Test
@@ -58,10 +57,8 @@
     assertThat(eval("l[-1]")).isEqualTo("c");
     assertThat(eval("l[-2]")).isEqualTo("b");
     assertThat(eval("l[-3]")).isEqualTo("a");
-    checkEvalError("Index out of range (index is -4, but sequence has 3 elements)",
-        "l[-4]");
-    checkEvalError("Index out of range (index is -1, but sequence has 0 elements)",
-        "[][-1]");
+    checkEvalError("index out of range (index is -4, but sequence has 3 elements)", "l[-4]");
+    checkEvalError("index out of range (index is -1, but sequence has 0 elements)", "[][-1]");
   }
 
   @SuppressWarnings("unchecked")
@@ -141,7 +138,7 @@
     assertThat(listEval("l[-10:5:-1]")).isEmpty();
     assertThat(listEval("l[1:-8:-1]")).containsExactly("b", "a").inOrder();
 
-    checkEvalError("Slice step cannot be zero", "l[2:5:0]");
+    checkEvalError("slice step cannot be zero", "l[2:5:0]");
   }
 
   @Test