Use PKG_CONFIG_LIBDIR to force pkg-config to use sysroot only

build/config/linux/pkg-config.py

Index: build/config/linux/pkg-config.py
diff --git a/build/config/linux/pkg-config.py b/build/config/linux/pkg-config.py
index d707c5f1e32c8fdb08a5cec59df1484cf66986c2..3374046029ff41474da3ff65cb4900a29331c533 100755
--- a/build/config/linux/pkg-config.py
+++ b/build/config/linux/pkg-config.py
@@ -42,7 +42,7 @@ from optparse import OptionParser
 
 
 def SetConfigPath(options):
-  """Set the PKG_CONFIG_PATH environment variable.
+  """Set the PKG_CONFIG_LIBDIR environment variable.
   This takes into account any sysroot and architecture specification from the
   options on the given command line."""
 
@@ -55,13 +55,11 @@ def SetConfigPath(options):
     print "You must specify an architecture via -a if using a sysroot."
     sys.exit(1)
 
-  # Add the sysroot path to the environment's PKG_CONFIG_PATH
+  # Add the sysroot path to the environment's PKG_CONFIG_LIBDIR

[Lei Zhang, 2016/01/12 23:01:50]

More like overwrite than add.

[Sam Clegg, 2016/01/12 23:25:12]

Done

   config_path = sysroot + '/usr/' + options.system_libdir + '/pkgconfig'
   config_path += ':' + sysroot + '/usr/share/pkgconfig'
-  if 'PKG_CONFIG_PATH' in os.environ:
-    os.environ['PKG_CONFIG_PATH'] += ':' + config_path
-  else:
-    os.environ['PKG_CONFIG_PATH'] = config_path
+  os.environ['PKG_CONFIG_LIBDIR'] = config_path
+  return config_path
 
 
 def GetPkgConfigPrefixToStrip(args):
@@ -131,9 +129,9 @@ def main():
       strip_out.append(re.compile(regexp))
 
   if options.sysroot:
-    SetConfigPath(options)
+    libdir = SetConfigPath(options)
     if options.debug:
-      sys.stderr.write('PKG_CONFIG_PATH=%s\n' % os.environ['PKG_CONFIG_PATH'])
+      sys.stderr.write('PKG_CONFIG_LIBDIR=%s\n' % libdir)
     prefix = GetPkgConfigPrefixToStrip(args)
   else:
     prefix = ''
@@ -150,28 +148,32 @@ def main():
     return 0
 
   if options.libdir:
+    cmd = [options.pkg_config, "--variable=libdir"] + args
+    if options.debug:
+      sys.stderr.write('Running: %s\n' % cmd)
     try:
-      libdir = subprocess.check_output([options.pkg_config,
-                                        "--variable=libdir"] +
-                                       args)
+      libdir = subprocess.check_output(cmd)
     except:
       print "Error from pkg-config."
       return 1
     sys.stdout.write(libdir.strip())
     return 0
 
+  cmd = [options.pkg_config, "--cflags", "--libs"] + args
+  if options.debug:
+    sys.stderr.write('Running: %s\n' % ' '.join(cmd))
+
   try:
-    flag_string = subprocess.check_output(
-        [ options.pkg_config, "--cflags", "--libs" ] +
-        args)
-    # For now just split on spaces to get the args out. This will break if
-    # pkgconfig returns quoted things with spaces in them, but that doesn't seem
-    # to happen in practice.
-    all_flags = flag_string.strip().split(' ')
+    flag_string = subprocess.check_output(cmd)
   except:
-    print "Could not run pkg-config."
+    sys.stderr.write('Could not run pkg-config.\n')
     return 1
 
+  # For now just split on spaces to get the args out. This will break if
+  # pkgconfig returns quoted things with spaces in them, but that doesn't seem
+  # to happen in practice.
+  all_flags = flag_string.strip().split(' ')
+
 
   sysroot = options.sysroot
   if not sysroot: