nixpkgs/pkgs/applications/audio/rhvoice/honor_nix_environment.patch

diff --git a/SConstruct b/SConstruct
index 3ad4d9a..fb02365 100644
--- a/SConstruct
+++ b/SConstruct
@@ -94,11 +94,8 @@ def CheckWiX(context):
     return result
 
 def get_spd_module_dir():
-    env = Environment()
-    try:
-        return env.ParseConfig("pkg-config speech-dispatcher --variable=modulebindir", passthru)
-    except:
-        return False
+    # cannot write to ${speechd}/libexec/speech-dispatcher-modules
+    return os.path.join(os.environ["out"], "libexec/speech-dispatcher-modules")
 
 def validate_spd_version(key,val,env):
     m=re.match(r"^\d+\.\d+",val)
@@ -208,9 +205,9 @@ def create_base_env(user_vars):
     env_args["package_name"]="RHVoice"
     env_args["CPPDEFINES"]=[("RHVOICE","1")]
     env=Environment(**env_args)
-    if env["dev"]:
-        env["prefix"]=os.path.abspath("local")
-        env["RPATH"]=env.Dir("$libdir").abspath
+    env.PrependENVPath("PATH", os.environ["PATH"])
+    env["ENV"]["PKG_CONFIG_PATH"]=os.environ["PKG_CONFIG_PATH"]
+    env["RPATH"]=env.Dir("$libdir").abspath
     env["package_version"]=get_version(env["release"])
     env.Append(CPPDEFINES=("PACKAGE",env.subst(r'\"$package_name\"')))
     if env["PLATFORM"]=="win32":