workaround for problem with random numers and MPI

nifty5/extra.py

@@ -72,7 +72,7 @@ def _full_implementation(op, domain_dtype, target_dtype, atol, rtol,
 def _check_linearity(op, domain_dtype, atol, rtol):
     fld1 = from_random("normal", op.domain, dtype=domain_dtype)
     fld2 = from_random("normal", op.domain, dtype=domain_dtype)
-    alpha = np.random.random()
+    alpha = np.random.random() # FIXME: this can break badly with MPI!
     val1 = op(alpha*fld1+fld2)
     val2 = alpha*op(fld1)+op(fld2)
     _assert_allclose(val1, val2, atol=atol, rtol=rtol)

test/test_operators/test_adjoint.py

@@ -37,6 +37,7 @@ _pow_spaces = [ift.PowerSpace(ift.RGSpace((17, 38), harmonic=True))]
 pmp = pytest.mark.parametrize
 dtype = list2fixture([np.float64, np.complex128])
 
+np.random.seed(42)
 
 @pmp('sp', _p_RG_spaces)
 def testLOSResponse(sp, dtype):