--- a/langkit/compile_context.py	2018-07-04 19:17:08.329346507 +0200
+++ b/langkit/compile_context.py	2018-07-04 19:17:57.276615724 +0200
@@ -1684,7 +1684,7 @@
             generate_lexer
         ):
             quex_py_file = path.join(os.environ["QUEX_PATH"], "quex-exe.py")
-            subprocess.check_call([sys.executable, quex_py_file, "-i",
+            subprocess.check_call(["quex", "-i",
                                    quex_file,
                                    "-o", "quex_lexer",
                                    "--buffer-element-size", "4",
--- a/langkit/libmanage.py	2018-11-20 21:38:03.042086783 +0100
+++ b/langkit/libmanage.py	2018-11-20 21:39:50.562273656 +0100
@@ -682,6 +682,8 @@
 
         result = ['-XBUILD_MODE={}'.format(build_mode),
                   '-XLIBRARY_TYPE={}'.format(library_type),
+                  '-XGPR_BUILD={}'.format(library_type),
+                  '-XGNATCOLL_CORE_BUILD={}'.format(library_type),
                   '-XXMLADA_BUILD={}'.format(library_type)]
 
         enable_build_warnings = getattr(args, 'enable_build_warnings', False)
--- a/testsuite/python_support/utils.py	2018-11-20 21:41:46.156324084 +0100
+++ b/testsuite/python_support/utils.py	2018-11-20 21:42:26.049651194 +0100
@@ -203,7 +203,8 @@
                 main_sources=', '.join('"{}"'.format(m) for m in ada_main)
             ))
         run('gprbuild', '-Pgen', '-q', '-p',
-            '-XLIBRARY_TYPE=relocatable', '-XXMLADA_BUILD=relocatable')
+            '-XLIBRARY_TYPE=relocatable', '-XGPR_BUILD=relocatable',
+            '-XXMLADA_BUILD=relocatable')
 
         for i, m in enumerate(ada_main):
             assert m.endswith('.adb')
--- a/testsuite/testsuite_support/__init__.py	2018-11-20 21:45:08.828905205 +0100
+++ b/testsuite/testsuite_support/__init__.py	2018-11-20 21:46:10.837858988 +0100
@@ -110,7 +110,9 @@
         # Build Langkit_Support so that each testcase does not try to build it
         # in parallel.
         if not self.global_env['options'].disable_tear_up_builds:
-            gargs = ['-p', '-P', self.langkit_support_project_file]
+            gargs = ['-p']
+            gargs = gargs + ['-XGPR_BUILD=relocatable']
+            gargs = gargs + ['-P', self.langkit_support_project_file]
             cargs = ['-cargs', '-O0', '-g']
             if self.coverage_enabled:
                 gargs.append('--subdirs=gnatcov')
--- a/testsuite/testsuite_support/base_driver.py	2018-11-20 22:04:54.199973719 +0100
+++ b/testsuite/testsuite_support/base_driver.py	2018-11-20 22:05:26.498436100 +0100
@@ -312,7 +312,9 @@
 
         :param str project_file: Project file name.
         """
-        argv = ['gprbuild', '-P', project_file, '-p']
+        argv = ['gprbuild']
+        argv = argv + ['-XGPR_BUILD=relocatable']
+        argv = argv + ['-P', project_file, '-p']
         cargs = ['-O0', '-g', '-gnata']
         if self.coverage_enabled:
             argv.append('--subdirs=gnatcov')