Index: libraries/source/cxxtest-4.4/build.sh
--- libraries/source/cxxtest-4.4/build.sh.orig
+++ libraries/source/cxxtest-4.4/build.sh
@@ -40,7 +40,7 @@ fi
 
 # unpack
 rm -Rf "cxxtest-${PV}"
-tar -xf "cxxtest-${PV}.tar.gz"
+tar -xzf "cxxtest-${PV}.tar.gz"
 
 # patch
 patch -d "cxxtest-${PV}" -p1 <patches/0001-Add-Debian-python3-patch.patch
