Disable 'nvcc' tests to avoid test failure
on system with gcc-7+ enabled by default.
--- a/test/run
+++ b/test/run
@@ -425,2 +425,6 @@ else
 fi
+# Disable nvcc tests in Gentoo as nvcc requires gcc<7.
+# Not a default normally.
+REAL_NVCC=
+REAL_CUOBJDUMP=
 echo