# This patch is only applied if SymbiYosys isn't installed. Not sure if all
# `GrayCoderTestCase` will require it but it is probable all `FIFOFormalCase`
# will as SymbiYosys allows formal hardware verification.
#
# It isn't currently available in ChromiumOS and only 11 out of 605 tests are
# skipped so let's not depend on SymbiYosys for testing.

--- a/tests/test_lib_coding.py
+++ b/tests/test_lib_coding.py
@@ -116,12 +116,14 @@ class HammingDistanceSpec(Elaboratable):
         ]
         return m
 
-
+import unittest
 class GrayCoderTestCase(FHDLTestCase):
+    @unittest.skip("No SymbiYosys")
     def test_reversible(self):
         spec = ReversibleSpec(encoder_cls=GrayEncoder, decoder_cls=GrayDecoder, args=(16,))
         self.assertFormal(spec, mode="prove")
 
+    @unittest.skip("No SymbiYosys")
     def test_distance(self):
         spec = HammingDistanceSpec(distance=1, encoder_cls=GrayEncoder, args=(16,))
         self.assertFormal(spec, mode="prove")
diff --git a/tests/test_lib_fifo.py b/tests/test_lib_fifo.py
index 0e322c1..6d00922 100644
--- a/tests/test_lib_fifo.py
+++ b/tests/test_lib_fifo.py
@@ -236,7 +236,8 @@ class FIFOContractSpec(Elaboratable):
 
         return m
 
-
+import unittest
+@unittest.skip("No SymbiYosys")
 class FIFOFormalCase(FHDLTestCase):
     def check_sync_fifo(self, fifo):
         self.assertFormal(FIFOModelEquivalenceSpec(fifo, r_domain="sync", w_domain="sync"),