PKGBUILDs/extra/mesa/fix-install.diff

diff -u -r mesa/bin/install_megadrivers.py mesa-patched/bin/install_megadrivers.py
--- mesa/bin/install_megadrivers.py	2018-03-27 19:35:14.000000000 +0200
+++ mesa-patched/bin/install_megadrivers.py	2018-03-28 10:27:15.898280592 +0200
@@ -50,18 +50,13 @@
         print('installing {} to {}'.format(args.megadriver, driver))
         os.link(master, driver)
 
-        try:
-            ret = os.getcwd()
-            os.chdir(to)
-
-            name, ext = os.path.splitext(each)
-            while ext != '.so':
-                if os.path.exists(name):
-                    os.unlink(name)
-                os.symlink(driver, name)
-                name, ext = os.path.splitext(name)
-        finally:
-            os.chdir(ret)
+        name, ext = os.path.splitext(each)
+        while ext != '.so':
+            symlink = os.path.join(to, name)
+            if os.path.exists(symlink):
+                os.unlink(symlink)
+            os.symlink(each, symlink)
+            name, ext = os.path.splitext(name)
     os.unlink(master)