diff --git a/src/twisted/conch/test/test_agent.py b/src/twisted/conch/test/test_agent.py

index f5bf8f9a0d..153d9fe1c9 100644

--- a/src/twisted/conch/test/test_agent.py

+++ b/src/twisted/conch/test/test_agent.py

@@ -265,6 +265,7 @@ class AgentClientFailureTests(AgentTestBase):

 class AgentIdentityRequestsTests(AgentTestBase):

+    skip = "UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     Test operations against a server with identities already loaded.

     """

diff --git a/src/twisted/conch/test/test_cftp.py b/src/twisted/conch/test/test_cftp.py

index 5ffed395fd..f1b03b4aa8 100644

--- a/src/twisted/conch/test/test_cftp.py

+++ b/src/twisted/conch/test/test_cftp.py

@@ -932,6 +932,7 @@ class CFTPClientTestBase(SFTPTestBase):

 @skipIf(skipTests, "don't run w/o spawnProcess or cryptography")

 class OurServerCmdLineClientTests(CFTPClientTestBase):

+    skip = "Disabled in Fedora buildsys"

     """

     Functional tests which launch a SFTP server over TCP on localhost and check

     cftp command line interface using a spawned process.

@@ -1331,6 +1332,7 @@ class OurServerCmdLineClientTests(CFTPClientTestBase):

 @skipIf(skipTests, "don't run w/o spawnProcess or cryptography")

 class OurServerBatchFileTests(CFTPClientTestBase):

+    skip = "Disabled in Fedora buildsys"

     """

     Functional tests which launch a SFTP server over localhost and checks csftp

     in batch interface.

@@ -1437,6 +1439,7 @@ exit

 @skipIf(not which("ssh"), "no ssh command-line client available")

 @skipIf(not which("sftp"), "no sftp command-line client available")

 class OurServerSftpClientTests(CFTPClientTestBase):

+    skip = "Disabled in Fedora buildsys"

     """

     Test the sftp server against sftp command line client.

     """

diff --git a/src/twisted/conch/test/test_checkers.py b/src/twisted/conch/test/test_checkers.py

index 555ec6e7a0..c5d1f587d7 100644

--- a/src/twisted/conch/test/test_checkers.py

+++ b/src/twisted/conch/test/test_checkers.py

@@ -159,7 +159,7 @@ class SSHPublicKeyDatabaseTests(TestCase):

     Tests for L{SSHPublicKeyDatabase}.

     """

-    skip = euidSkip or dependencySkip

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     def setUp(self) -> None:

         self.checker = checkers.SSHPublicKeyDatabase()

@@ -802,7 +802,7 @@ class SSHPublicKeyCheckerTests(TestCase):

     Tests for L{checkers.SSHPublicKeyChecker}.

     """

-    skip = dependencySkip

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     def setUp(self):

         self.credentials = SSHPrivateKey(

diff --git a/src/twisted/conch/test/test_conch.py b/src/twisted/conch/test/test_conch.py

index b9614a4410..3b8d90323d 100644

--- a/src/twisted/conch/test/test_conch.py

+++ b/src/twisted/conch/test/test_conch.py

@@ -55,6 +55,7 @@ else:

 class FakeStdio:

+    skip = "Disabled in Fedora buildsys"

     """

     A fake for testing L{twisted.conch.scripts.conch.SSHSession.eofReceived} and

     L{twisted.conch.scripts.cftp.SSHSession.eofReceived}.

@@ -73,6 +74,7 @@ class FakeStdio:

 class StdioInteractingSessionTests(TestCase):

+    skip = "Disabled in Fedora buildsys"

     """

     Tests for L{twisted.conch.scripts.conch.SSHSession}.

     """

@@ -93,6 +95,7 @@ class StdioInteractingSessionTests(TestCase):

 class Echo(protocol.Protocol):

+    skip = "Disabled in Fedora buildsys"

     def connectionMade(self):

         log.msg("ECHO CONNECTION MADE")

@@ -106,10 +109,12 @@ class Echo(protocol.Protocol):

 class EchoFactory(protocol.Factory):

+    skip = "Disabled in Fedora buildsys"

     protocol = Echo

 class ConchTestOpenSSHProcess(protocol.ProcessProtocol):

+    skip = "Disabled in Fedora buildsys"

     """

     Test protocol for launching an OpenSSH client process.

@@ -153,6 +158,7 @@ class ConchTestOpenSSHProcess(protocol.ProcessProtocol):

 class ConchTestForwardingProcess(protocol.ProcessProtocol):

+    skip = "Disabled in Fedora buildsys"

     """

     Manages a third-party process which launches a server.

@@ -229,6 +235,7 @@ class ConchTestForwardingProcess(protocol.ProcessProtocol):

 class ConchTestForwardingPort(protocol.Protocol):

+    skip = "Disabled in Fedora buildsys"

     """

     Connects to server launched by a third-party process (managed by

     L{ConchTestForwardingProcess}) sends data, then reports whatever it

@@ -285,6 +292,7 @@ run()"""

 class ConchServerSetupMixin:

+    skip = "Disabled in Fedora buildsys"

     if not cryptography:

         skip = "can't run without cryptography"

@@ -360,6 +368,7 @@ class ConchServerSetupMixin:

 class ForwardingMixin(ConchServerSetupMixin):

+    skip = "Disabled in Fedora buildsys"

     """

     Template class for tests of the Conch server's ability to forward arbitrary

     protocols over SSH.

@@ -415,6 +424,7 @@ class ForwardingMixin(ConchServerSetupMixin):

 # pass.

 @implementer(ISession)

 class RekeyAvatar(ConchUser):

+    skip = "Disabled in Fedora buildsys"

     """

     This avatar implements a shell which sends 60 numbered lines to whatever

     connects to it, then closes the session with a 0 exit status.

@@ -483,6 +493,7 @@ class RekeyAvatar(ConchUser):

 class RekeyRealm:

+    skip = "Disabled in Fedora buildsys"

     """

     This realm gives out new L{RekeyAvatar} instances for any avatar request.

     """

@@ -492,6 +503,7 @@ class RekeyRealm:

 class RekeyTestsMixin(ConchServerSetupMixin):

+    skip = "Disabled in Fedora buildsys"

     """

     TestCase mixin which defines tests exercising L{SSHTransportBase}'s handling

     of rekeying messages.

@@ -517,6 +529,7 @@ class RekeyTestsMixin(ConchServerSetupMixin):

 class OpenSSHClientMixin:

+    skip = "Disabled in Fedora buildsys"

     if not which("ssh"):

         skip = "no ssh command-line client available"

@@ -566,6 +579,7 @@ class OpenSSHClientMixin:

 class OpenSSHKeyExchangeTests(ConchServerSetupMixin, OpenSSHClientMixin, TestCase):

+    skip = "Disabled in Fedora buildsys"

     """

     Tests L{SSHTransportBase}'s key exchange algorithm compatibility with

     OpenSSH.

@@ -658,6 +672,7 @@ class OpenSSHKeyExchangeTests(ConchServerSetupMixin, OpenSSHClientMixin, TestCas

 class OpenSSHClientForwardingTests(ForwardingMixin, OpenSSHClientMixin, TestCase):

+    skip = "Disabled in Fedora buildsys"

     """

     Connection forwarding tests run against the OpenSSL command line client.

     """

@@ -677,12 +692,14 @@ class OpenSSHClientForwardingTests(ForwardingMixin, OpenSSHClientMixin, TestCase

 class OpenSSHClientRekeyTests(RekeyTestsMixin, OpenSSHClientMixin, TestCase):

+    skip = "Disabled in Fedora buildsys"

     """

     Rekeying tests run against the OpenSSL command line client.

     """

 class CmdLineClientTests(ForwardingMixin, TestCase):

+    skip = "Disabled in Fedora buildsys"

     """

     Connection forwarding tests run against the Conch command line client.

     """

diff --git a/src/twisted/conch/test/test_endpoints.py b/src/twisted/conch/test/test_endpoints.py

index 5f6dd4a1b6..1e58d46a39 100644

--- a/src/twisted/conch/test/test_endpoints.py

+++ b/src/twisted/conch/test/test_endpoints.py

@@ -699,6 +699,7 @@ class SSHCommandClientEndpointTestsMixin:

 class NewConnectionTests(TestCase, SSHCommandClientEndpointTestsMixin):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     Tests for L{SSHCommandClientEndpoint} when using the C{newConnection}

     constructor.

@@ -1233,6 +1234,7 @@ class NewConnectionTests(TestCase, SSHCommandClientEndpointTestsMixin):

         self.assertTrue(client.transport.disconnecting)

     def test_agentAuthentication(self):

+        self.skip = "Disabled in Fedora buildsys"

         """

         If L{SSHCommandClientEndpoint} is initialized with an

         L{SSHAgentClient}, the agent is used to authenticate with the SSH

diff --git a/src/twisted/conch/test/test_keys.py b/src/twisted/conch/test/test_keys.py

index e479f99c5b..3a3a57d4da 100644

--- a/src/twisted/conch/test/test_keys.py

+++ b/src/twisted/conch/test/test_keys.py

@@ -42,6 +42,7 @@ def skipWithoutEd25519(f):

 class KeyTests(unittest.TestCase):

     if cryptography is None:

         skip = skipCryptography

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     def setUp(self):

         self.rsaObj = keys.Key._fromRSAComponents(

@@ -1420,6 +1421,7 @@ xEm4DxjEoaIp8dW/JOzXQ2EF+WaSOgdYsw3Ac+rnnjnNptCdOEDGP6QBkt+oXj4P

         self.assertRaises(keys.BadKeyError, keys.Key(self.rsaObj).toString, "bad_type")

     def test_signAndVerifyRSA(self):

+        self.skip = "Disabled in Fedora buildsys"

         """

         Signed data can be verified using RSA (with SHA-1, the default).

         """

@@ -1537,6 +1539,7 @@ xEm4DxjEoaIp8dW/JOzXQ2EF+WaSOgdYsw3Ac+rnnjnNptCdOEDGP6QBkt+oXj4P

         )

     def test_verifyRSA(self):

+        self.skip = "Disabled in Fedora buildsys"

         """

         A known-good RSA signature verifies successfully.

         """

diff --git a/src/twisted/conch/test/test_ssh.py b/src/twisted/conch/test/test_ssh.py

index 211feb7f22..f8ada799ab 100644

--- a/src/twisted/conch/test/test_ssh.py

+++ b/src/twisted/conch/test/test_ssh.py

@@ -544,6 +544,7 @@ if cryptography is not None:

 class SSHProtocolTests(unittest.TestCase):

+    skip = "Disabled in Fedora buildsys"

     """

     Tests for communication between L{SSHServerTransport} and

     L{SSHClientTransport}.

diff --git a/src/twisted/conch/test/test_transport.py b/src/twisted/conch/test/test_transport.py

index 570389f707..443f781989 100644

--- a/src/twisted/conch/test/test_transport.py

+++ b/src/twisted/conch/test/test_transport.py

@@ -1459,6 +1459,7 @@ class ServerSSHTransportBaseCase(ServerAndClientSSHTransportBaseCase):

 class ServerSSHTransportTests(ServerSSHTransportBaseCase, TransportTestCase):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     Tests for SSHServerTransport.

     """

@@ -2083,6 +2084,7 @@ class ServerSSHTransportDHGroupExchangeSHA1Tests(

     DHGroupExchangeSHA1Mixin,

     TransportTestCase,

 ):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     diffie-hellman-group-exchange-sha1 tests for SSHServerTransport.

     """

@@ -2093,6 +2095,7 @@ class ServerSSHTransportDHGroupExchangeSHA256Tests(

     DHGroupExchangeSHA256Mixin,

     TransportTestCase,

 ):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     diffie-hellman-group-exchange-sha256 tests for SSHServerTransport.

     """

@@ -2153,6 +2156,7 @@ class ServerSSHTransportECDHBaseCase(ServerSSHTransportBaseCase):

 class ServerSSHTransportECDHTests(

     ServerSSHTransportECDHBaseCase, ECDHMixin, TransportTestCase

 ):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     ecdh-sha2-nistp256 tests for SSHServerTransport.

     """

@@ -2162,6 +2166,7 @@ class ServerSSHTransportECDHTests(

 class ServerSSHTransportCurve25519SHA256Tests(

     ServerSSHTransportECDHBaseCase, Curve25519SHA256Mixin, TransportTestCase

 ):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     curve25519-sha256 tests for SSHServerTransport.

     """

@@ -2194,6 +2199,8 @@ class ClientSSHTransportBaseCase(ServerAndClientSSHTransportBaseCase):

 class ClientSSHTransportTests(ClientSSHTransportBaseCase, TransportTestCase):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

+

     """

     Tests for SSHClientTransport.

     """

@@ -2677,6 +2684,7 @@ class ClientSSHTransportDHGroupExchangeSHA1Tests(

     DHGroupExchangeSHA1Mixin,

     TransportTestCase,

 ):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     diffie-hellman-group-exchange-sha1 tests for SSHClientTransport.

     """

@@ -2687,6 +2695,7 @@ class ClientSSHTransportDHGroupExchangeSHA256Tests(

     DHGroupExchangeSHA256Mixin,

     TransportTestCase,

 ):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     diffie-hellman-group-exchange-sha256 tests for SSHClientTransport.

     """

@@ -2781,6 +2790,7 @@ class ClientSSHTransportECDHBaseCase(ClientSSHTransportBaseCase):

 class ClientSSHTransportECDHTests(

     ClientSSHTransportECDHBaseCase, ECDHMixin, TransportTestCase

 ):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     ecdh-sha2-nistp256 tests for SSHClientTransport.

     """

@@ -2790,6 +2800,7 @@ class ClientSSHTransportECDHTests(

 class ClientSSHTransportCurve25519SHA256Tests(

     ClientSSHTransportECDHBaseCase, Curve25519SHA256Mixin, TransportTestCase

 ):

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

     """

     curve25519-sha256 tests for SSHClientTransport.

     """

@@ -3012,6 +3023,7 @@ class SSHCiphersTests(TestCase):

 class TransportLoopbackTests(TestCase):

+    skip = "Disabled in Fedora buildsys"

     """

     Test the server transport and client transport against each other,

     """

diff --git a/src/twisted/conch/test/test_userauth.py b/src/twisted/conch/test/test_userauth.py

index 825b5a2634..cf1005468e 100644

--- a/src/twisted/conch/test/test_userauth.py

+++ b/src/twisted/conch/test/test_userauth.py

@@ -237,6 +237,8 @@ class SSHUserAuthServerTests(unittest.TestCase):

     if keys is None:

         skip = "cannot run without cryptography"

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

+

     def setUp(self):

         self.realm = Realm()

         self.portal = Portal(self.realm)

@@ -616,6 +618,8 @@ class SSHUserAuthClientTests(unittest.TestCase):

     if keys is None:

         skip = "cannot run without cryptography"

+    skip = "Fedora UnsupportedAlgorithm: sha1 is not supported per crypto policy"

+

     def setUp(self):

         self.authClient = ClientUserAuth(b"foo", FakeTransport.Service())

         self.authClient.transport = FakeTransport(None)

@@ -901,6 +905,7 @@ class SSHUserAuthClientTests(unittest.TestCase):

 class LoopbackTests(unittest.TestCase):

+    skip = "Disabled in Fedora buildsys"

     if keys is None:

         skip = "cannot run without cryptography"

diff --git a/src/twisted/test/test_failure.py b/src/twisted/test/test_failure.py

index 8b8e55be64..5b510001cd 100644

--- a/src/twisted/test/test_failure.py

+++ b/src/twisted/test/test_failure.py

@@ -19,7 +19,10 @@ from types import TracebackType

 from typing import Any, Generator, cast

 from unittest import skipIf

-from cython_test_exception_raiser import raiser

+try:

+    from cython_test_exception_raiser import raiser

+except ModuleNotFoundError:

+    raiser = None

 from twisted.python import failure, reflect

 from twisted.trial.unittest import SynchronousTestCase

diff --git a/src/twisted/test/test_tcp.py b/src/twisted/test/test_tcp.py

index 91114da6e8..dddc5d342e 100644

--- a/src/twisted/test/test_tcp.py

+++ b/src/twisted/test/test_tcp.py

@@ -373,6 +373,7 @@ class ListeningTests(TestCase):

 class LoopbackTests(TestCase):

+    skip = "Disabled in Fedora buildsys"

     """

     Test loopback connections.

     """

diff --git a/src/twisted/test/test_udp.py b/src/twisted/test/test_udp.py

index 4cb43f2fd0..4a90a8dabe 100644

--- a/src/twisted/test/test_udp.py

+++ b/src/twisted/test/test_udp.py

@@ -577,6 +577,8 @@ class MulticastTests(TestCase):

     if not interfaces.IReactorMulticast(reactor, None):

         skip = "This reactor does not support multicast"

+    skip = "Disabled in Fedora buildsys"

+

     def setUp(self):

         self.server = Server()

         self.client = Client()