Turn off test_value when checking for beta init.

theano/tensor/blas_c.py

@@ -719,6 +719,11 @@ def check_force_gemv_init():
         beta*aa which will result in NaN's in the result, then we need intialize
         the memory to zeros.
         """
+        tv = theano.config.compute_test_value
+        tvo = theano.config.compute_test_value_opt
+        theano.config.compute_test_value = 'off'
+        theano.config.compute_test_value_opt = 'off'
+        try:
             aa = T.vector('aa')
             yy = T.vector('yy')
             xx = T.matrix('xx')
@@ -727,6 +732,9 @@ def check_force_gemv_init():
                 gemv_no_inplace(aa, 1., xx, yy, 0.),
                 theano.compile.Mode(optimizer='fast_compile')
                 )
+        finally:
+            theano.config.compute_test_value = tv
+            theano.config.compute_test_value_opt = tvo
 
         # Here we introduce NaNs into the data, if they are returned by the BLAS
         # then we want gemv_c_code to initiliaze the memory to 0 so that we