diff --git a/pymake/pymake.py b/pymake/pymake.py
index ecb50b4..00ce0fb 100644
--- a/pymake/pymake.py
+++ b/pymake/pymake.py
@@ -236,7 +236,7 @@ def compress_targets(self):
                     # set appdir based on first target, assumes that the path
                     # for all of the targets are the same
                     if appdir is None:
-                        appdir = os.path.dirname(target)
+                        appdir = str(Path(target).parent)
             # determine files in appdir if no applications build at this
             # time (--keep command line argument)
             else:
@@ -529,6 +529,8 @@ def set_build_target_bool(self, target=None):
             target = self.target
 
         if self.appdir is not None:
+            # os.path.dirname rather than Path.parent, because a target
+            # with no directory has to compare unequal to an appdir of "."
             if os.path.dirname(self.target) != self.appdir:
                 target = str(Path(self.appdir) / Path(target).name)
 
@@ -646,7 +648,7 @@ def _set_extrafiles(self):
 
             # evaluate extrafiles type
             if extrafiles:
-                srcdir = os.path.abspath(self.srcdir)
+                srcdir = Path(self.srcdir).absolute()
                 if isinstance(extrafiles, list):
                     for idx, value in enumerate(extrafiles):
                         fpth = str(Path(srcdir) / value)
@@ -820,6 +822,8 @@ def update_build_targets(self):
         -------
 
         """
+        # os.path.abspath rather than Path.absolute, because it removes the
+        # ".." segments and so two spellings of a target count as one
         if os.path.abspath(self.target) not in self.build_targets:
             if self.verbose:
                 print(f"adding {self.target} to build_targets list")
diff --git a/pymake/pymake_base.py b/pymake/pymake_base.py
index 832d53e..53711b1 100644
--- a/pymake/pymake_base.py
+++ b/pymake/pymake_base.py
@@ -1060,7 +1060,9 @@ def _write_makedefaults(
         line += "endif\n\n"
         f.write(line)
 
-        # get path to executable
+        # get path to executable. os.path.dirname rather than
+        # Path.parent, because a target with no directory has to give
+        # the empty string here rather than "."
         dpth = os.path.dirname(target)
         if len(dpth) > 0:
             dpth = os.path.relpath(dpth, make_dir)
diff --git a/pymake/pymake_build_apps.py b/pymake/pymake_build_apps.py
index 2803a5c..ecee088 100644
--- a/pymake/pymake_build_apps.py
+++ b/pymake/pymake_build_apps.py
@@ -26,7 +26,6 @@
 
 """
 
-import os
 import shutil
 import sys
 from datetime import datetime
@@ -118,7 +117,7 @@ def build_apps(
     if appdir is None:
         base_pth = "."
     else:
-        base_pth = os.path.dirname(appdir)
+        base_pth = str(Path(appdir).parent)
 
     # set the meson directory if a pymake object was not passed in
     if pymake_object is None:
diff --git a/pymake/utils/_meson_build.py b/pymake/utils/_meson_build.py
index 6fe21dd..69c2d6f 100644
--- a/pymake/utils/_meson_build.py
+++ b/pymake/utils/_meson_build.py
@@ -229,6 +229,8 @@ def meson_setup(
         else:
             command_list.append("--prefix=$(pwd)")
 
+        # os.path, because the install directory is relative to the build
+        # file and Path.relative_to cannot walk up before python 3.12
         libdir = os.path.relpath(os.path.abspath(appdir), os.path.abspath(mesondir))
         command_list.append(f"--libdir={libdir}")
         command_list.append(f"--bindir={libdir}")
diff --git a/pymake/utils/_usgs_src_update.py b/pymake/utils/_usgs_src_update.py
index 3c75fea..3316df6 100644
--- a/pymake/utils/_usgs_src_update.py
+++ b/pymake/utils/_usgs_src_update.py
@@ -596,12 +596,10 @@ def _update_vs2dt_files(srcdir, **kwargs):
 
     """
     # move the main source into the source directory
-    f1 = Path(srcdir) / ".." / "vs2dt3_3.f"
-    f1 = os.path.abspath(f1)
+    f1 = (Path(srcdir).parent / "vs2dt3_3.f").absolute()
     if not Path(f1).is_file():
         raise OSError(f"{f1} does not exist")
-    f2 = Path(srcdir) / "vs2dt3_3.f"
-    f2 = os.path.abspath(f2)
+    f2 = (Path(srcdir) / "vs2dt3_3.f").absolute()
     shutil.move(f1, f2)
     if not Path(f2).is_file():
         raise OSError(f"{f2} does not exist")
diff --git a/pymake/utils/usgsprograms.py b/pymake/utils/usgsprograms.py
index b98af6d..4f67008 100644
--- a/pymake/utils/usgsprograms.py
+++ b/pymake/utils/usgsprograms.py
@@ -103,7 +103,6 @@ def _build_usgs_database(self):
         -------
 
         """
-        # pth = os.path.dirname(os.path.abspath(pymake.__file__))
         fpth = Path(__file__).parent / PROGRAM_DATA_FILE
         with open(fpth, "rb") as f:
             programs = tomllib.load(f)["program"]