- Issue #17086: Backport the patches from the 3.3 branch to cross-build
  the package.
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index 9442d39..d74ca39 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -116,6 +116,10 @@
 if os.name == "nt" and "\\pcbuild\\amd64" in _PROJECT_BASE[-14:].lower():
     _PROJECT_BASE = _safe_realpath(os.path.join(_PROJECT_BASE, pardir, pardir))
 
+# set for cross builds
+if "_PYTHON_PROJECT_BASE" in os.environ:
+    # the build directory for posix builds
+    _PROJECT_BASE = os.path.normpath(os.path.abspath("."))
 def is_python_build():
     for fn in ("Setup.dist", "Setup.local"):
         if os.path.isfile(os.path.join(_PROJECT_BASE, "Modules", fn)):
@@ -507,6 +511,10 @@
             return 'win-ia64'
         return sys.platform
 
+    # Set for cross builds explicitly
+    if "_PYTHON_HOST_PLATFORM" in os.environ:
+        return os.environ["_PYTHON_HOST_PLATFORM"]
+
     if os.name != "posix" or not hasattr(os, 'uname'):
         # XXX what about the architecture? NT is Intel or Alpha,
         # Mac OS is M68k or PPC, etc.