diff --git a/platformio/builder/tools/piolib.py b/platformio/builder/tools/piolib.py
index 6c813313..0a75d935 100644
--- a/platformio/builder/tools/piolib.py
+++ b/platformio/builder/tools/piolib.py
@@ -111,7 +111,7 @@ class LibBuilderFactory(object):
         return []
 
 
-class LibBuilderBase(object):
+class LibBuilderBase:
 
     CLASSIC_SCANNER = SCons.Scanner.C.CScanner()
     CCONDITIONAL_SCANNER = SCons.Scanner.C.CConditionalScanner()
@@ -514,7 +514,7 @@ class ArduinoLibBuilder(LibBuilderBase):
         return os.path.join(self.path, "include")
 
     def get_include_dirs(self):
-        include_dirs = LibBuilderBase.get_include_dirs(self)
+        include_dirs = super().get_include_dirs()
         if os.path.isdir(os.path.join(self.path, "src")):
             return include_dirs
         if os.path.isdir(os.path.join(self.path, "utility")):
@@ -612,7 +612,7 @@ class MbedLibBuilder(LibBuilderBase):
         return LibBuilderBase.src_dir.fget(self)  # pylint: disable=no-member
 
     def get_include_dirs(self):
-        include_dirs = LibBuilderBase.get_include_dirs(self)
+        include_dirs = super().get_include_dirs()
         if self.path not in include_dirs:
             include_dirs.append(self.path)
 
@@ -833,7 +833,7 @@ class PlatformIOLibBuilder(LibBuilderBase):
         return util.items_in_list(frameworks, self._manifest.get("frameworks") or ["*"])
 
     def get_include_dirs(self):
-        include_dirs = LibBuilderBase.get_include_dirs(self)
+        include_dirs = super().get_include_dirs()
 
         # backwards compatibility with PlatformIO 2.0
         if (
@@ -872,14 +872,14 @@ class ProjectAsLibBuilder(LibBuilderBase):
         project_include_dir = self.env.subst("$PROJECT_INCLUDE_DIR")
         if os.path.isdir(project_include_dir):
             include_dirs.append(project_include_dir)
-        for include_dir in LibBuilderBase.get_include_dirs(self):
+        for include_dir in super().get_include_dirs():
             if include_dir not in include_dirs:
                 include_dirs.append(include_dir)
         return include_dirs
 
     def get_search_files(self):
         # project files
-        items = LibBuilderBase.get_search_files(self)
+        items = super().get_search_files()
         # test files
         if "test" in self.env.GetBuildType():
             items.extend(
@@ -994,7 +994,7 @@ class ProjectAsLibBuilder(LibBuilderBase):
 
     def build(self):
         self.is_built = True  # do not build Project now
-        result = LibBuilderBase.build(self)
+        result = super().build()
         self.env.PrependUnique(CPPPATH=self.get_include_dirs())
         return result
 
diff --git a/platformio/builder/tools/platformio.py b/platformio/builder/tools/platformio.py
index 12e57f69..0c943319 100644
--- a/platformio/builder/tools/platformio.py
+++ b/platformio/builder/tools/platformio.py
@@ -168,7 +168,7 @@ def ProcessProjectDeps(env):
     if not env.get("PIOBUILDFILES") and not COMMAND_LINE_TARGETS:
         sys.stderr.write(
             "Error: Nothing to build. Please put your source code files "
-            "to '%s' folder\n" % env.subst("$PROJECT_SRC_DIR")
+            "to the '%s' folder\n" % env.subst("$PROJECT_SRC_DIR")
         )
         env.Exit(1)
 
@@ -321,23 +321,16 @@ def BuildFrameworks(env, frameworks):
         )
         env.Exit(1)
 
-    board_frameworks = env.BoardConfig().get("frameworks", [])
-    if frameworks == ["platformio"]:
-        if board_frameworks:
-            frameworks.insert(0, board_frameworks[0])
-        else:
-            sys.stderr.write("Error: Please specify `board` in `platformio.ini`\n")
-            env.Exit(1)
-
-    for f in frameworks:
-        if f == "arduino":
-            # Arduino IDE appends .o the end of filename
+    supported_frameworks = env.BoardConfig().get("frameworks", [])
+    for name in frameworks:
+        if name == "arduino":
+            # Arduino IDE appends .o to the end of filename
             Builder.match_splitext = scons_patched_match_splitext
             if "nobuild" not in COMMAND_LINE_TARGETS:
                 env.ConvertInoToCpp()
 
-        if f in board_frameworks:
-            SConscript(env.GetFrameworkScript(f), exports="env")
+        if name in supported_frameworks:
+            SConscript(env.GetFrameworkScript(name), exports="env")
         else:
             sys.stderr.write("Error: This board doesn't support %s framework!\n" % f)
             env.Exit(1)
diff --git a/platformio/test/runners/googletest.py b/platformio/test/runners/googletest.py
index 70e237e5..11e51ff6 100644
--- a/platformio/test/runners/googletest.py
+++ b/platformio/test/runners/googletest.py
@@ -22,7 +22,7 @@ from platformio.test.result import TestCase, TestCaseSource, TestStatus
 from platformio.test.runners.base import TestRunnerBase
 
 
-class DoctestTestCaseParser:
+class GoogletestTestCaseParser:
 
     # Examples:
     # [ RUN      ] FooTest.Bar
@@ -95,7 +95,7 @@ class GoogletestTestRunner(TestRunnerBase):
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self._tc_parser = DoctestTestCaseParser()
+        self._tc_parser = GoogletestTestCaseParser()
         os.environ["GTEST_COLOR"] = "no"  # disable ANSI symbols
 
     def configure_build_env(self, env):