Disable-platform-guessing in setup.py

docs/installation.rst

@@ -202,7 +202,12 @@ Build Options
   the libraries are not found. Webpmux (WebP metadata) relies on WebP
   support. Tcl and Tk also must be used together.
 
-* Build flags: ``--debug``. Adds a debugging flag to the include and
+* Build flag: ``--disable-platform-guessing``. Skips all of the
+  platform dependent guessing of include and library directories for
+  automated build systems that configure the proper paths in the
+  environment variables (e.g. Buildroot).
+
+* Build flag: ``--debug``. Adds a debugging flag to the include and
   library search process to dump all paths searched for and found to
   stdout.
 

setup.py

@@ -146,9 +146,13 @@ def __iter__(self):
         ('disable-%s' % x, None, 'Disable support for %s' % x) for x in feature
     ] + [
         ('enable-%s' % x, None, 'Enable support for %s' % x) for x in feature
-    ] + [('debug', None, 'Debug logging')]
+    ] + [
+        ('disable-platform-guessing', None, 'Disable platform guessing on Linux'),
+        ('debug', None, 'Debug logging')
+    ]
 
     def initialize_options(self):
+        self.disable_platform_guessing = None
         build_ext.initialize_options(self)
         for x in self.feature:
             setattr(self, 'disable_%s' % x, None)
@@ -220,7 +224,10 @@ def build_extensions(self):
         #
         # add platform directories
 
-        if sys.platform == "cygwin":
+        if self.disable_platform_guessing:
+            pass
+
+        elif sys.platform == "cygwin":
             # pythonX.Y.dll.a is in the /usr/lib/pythonX.Y/config directory
             _add_directory(library_dirs,
                            os.path.join("/usr/lib", "python%s" %
@@ -318,10 +325,10 @@ def build_extensions(self):
                     raise ValueError(
                         "Unable to identify Linux platform: `%s`" % platform_)
 
-            # XXX Kludge. Above /\ we brute force support multiarch. Here we
-            # try Barry's more general approach. Afterward, something should
-            # work ;-)
-            self.add_multiarch_paths()
+                # XXX Kludge. Above /\ we brute force support multiarch. Here we
+                # try Barry's more general approach. Afterward, something should
+                # work ;-)
+                self.add_multiarch_paths()
 
         elif sys.platform.startswith("gnu"):
             self.add_multiarch_paths()
@@ -382,16 +389,18 @@ def build_extensions(self):
 
         # look for tcl specific subdirectory (e.g debian)
         if _tkinter:
-            tcl_dir = "/usr/include/tcl" + TCL_VERSION
-            if os.path.isfile(os.path.join(tcl_dir, "tk.h")):
-                _add_directory(include_dirs, tcl_dir)
+            if not self.disable_platform_guessing:
+                tcl_dir = "/usr/include/tcl" + TCL_VERSION
+                if os.path.isfile(os.path.join(tcl_dir, "tk.h")):
+                    _add_directory(include_dirs, tcl_dir)
 
         # standard locations
-        _add_directory(library_dirs, "/usr/local/lib")
-        _add_directory(include_dirs, "/usr/local/include")
+        if not self.disable_platform_guessing:
+            _add_directory(library_dirs, "/usr/local/lib")
+            _add_directory(include_dirs, "/usr/local/include")
 
-        _add_directory(library_dirs, "/usr/lib")
-        _add_directory(include_dirs, "/usr/include")
+            _add_directory(library_dirs, "/usr/lib")
+            _add_directory(include_dirs, "/usr/include")
 
         # on Windows, look for the OpenJPEG libraries in the location that
         # the official installer puts them