work around a bug in scons < 3.0.2

Signed-off-by: Nils Philippsen <nils@tiptoe.de>

libffado.spec

@@ -1,7 +1,7 @@
 Summary:        Free firewire audio driver library
 Name:           libffado
 Version:        2.4.3
-Release:        1%{?dist}
+Release:        2%{?dist}
 # src/libutil/float_cast.h is LGPLv2+.
 # The rest is (GPLv2 or GPLv3)
 License:        LGPLv2+ and (GPLv2 or GPLv3)
@@ -67,6 +67,11 @@ Applications and utilities for use with libffado.
 %prep
 %setup -q
 
+# Work around a bug in scons < 3.0.2
+if %{__python3} -c 'import SCons; import sys; sys.exit(not tuple(int(d) for d in SCons.__version__.split(".")) < (3, 0, 2))'; then
+    sed -i '/^CacheDir/d' SConstruct
+fi
+
 # We don't want to install all tests
 sed -i '/Install/d' tests/{,*/}SConscript
 
@@ -155,6 +160,9 @@ appstream-util validate-relax --nonet \
 
 
 %changelog
+* Sat May 30 2020 Nils Philippsen <nils@tiptoe.de> - 2.4.3-2
+- work around a bug in scons < 3.0.2
+
 * Fri May 29 2020 Nils Philippsen <nils@tiptoe.de> - 2.4.3-1
 - version 2.4.3