diff -Naur Python-3.8.0-orig/Lib/distutils/spawn.py Python-3.8.0/Lib/distutils/spawn.py
--- Python-3.8.0-orig/Lib/distutils/spawn.py	2019-10-14 16:34:47.000000000 +0300
+++ Python-3.8.0/Lib/distutils/spawn.py	2019-10-22 10:00:23.260677500 +0300
@@ -12,6 +12,7 @@
 from distutils.errors import DistutilsPlatformError, DistutilsExecError
 from distutils.debug import DEBUG
 from distutils import log
+from subprocess import list2cmdline
 
 def spawn(cmd, search_path=1, verbose=0, dry_run=0):
     """Run another program, specified as a command list 'cmd', in a new process.
@@ -43,17 +44,13 @@
 def _nt_quote_args(args):
     """Quote command-line arguments for DOS/Windows conventions.
 
-    Just wraps every argument which contains blanks in double quotes, and
-    returns a new argument list.
+    Defer to subprocess module's list2cmdline as the logic is
+    complex. The previous implementation here failed to handle
+    -DG_LOG_DOMAIN="GEGL-"__FILE__ which was encountered in MSYS2
+    while building the gobject-introspection part of GEGL 0.3.4.
     """
-    # XXX this doesn't seem very robust to me -- but if the Windows guys
-    # say it'll work, I guess I'll have to accept it.  (What if an arg
-    # contains quotes?  What other magic characters, other than spaces,
-    # have to be escaped?  Is there an escaping mechanism other than
-    # quoting?)
     for i, arg in enumerate(args):
-        if ' ' in arg:
-            args[i] = '"%s"' % arg
+        args[i] = list2cmdline([args[i]])
     return args
 
 def _spawn_nt(cmd, search_path=1, verbose=0, dry_run=0):
diff -Naur Python-3.8.0-orig/setup.py Python-3.8.0/setup.py
--- Python-3.8.0-orig/setup.py	2019-10-14 16:34:47.000000000 +0300
+++ Python-3.8.0/setup.py	2019-10-22 10:00:23.666278200 +0300
@@ -1421,11 +1421,7 @@
                 '_sqlite/statement.c',
                 '_sqlite/util.c', ]
 
-            sqlite_defines = []
-            if not MS_WINDOWS:
-                sqlite_defines.append(('MODULE_NAME', '"sqlite3"'))
-            else:
-                sqlite_defines.append(('MODULE_NAME', '\\"sqlite3\\"'))
+            sqlite_defines = [('MODULE_NAME', '"sqlite3"')]
 
             # Enable support for loadable extensions in the sqlite3 module
             # if --enable-loadable-sqlite-extensions configure option is used.