sage: disable intermittent test

pkgs/applications/science/math/sage/patches/disable-pexpect-intermittent-failure.patch

@@ -0,0 +1,29 @@
+diff --git a/src/sage/interfaces/singular.py b/src/sage/interfaces/singular.py
+index 88a33b0349..b3321f0bec 100644
+--- a/src/sage/interfaces/singular.py
++++ b/src/sage/interfaces/singular.py
+@@ -495,24 +495,6 @@ class Singular(ExtraTabCompletion, Expect):
+         """
+         Send an interrupt to Singular. If needed, additional
+         semi-colons are sent until we get back at the prompt.
+-
+-        TESTS:
+-
+-        The following works without restarting Singular::
+-
+-            sage: a = singular(1)
+-            sage: _ = singular._expect.sendline('1+')  # unfinished input
+-            sage: try:
+-            ....:     alarm(0.5)
+-            ....:     singular._expect_expr('>')  # interrupt this
+-            ....: except KeyboardInterrupt:
+-            ....:     pass
+-            Control-C pressed.  Interrupting Singular. Please wait a few seconds...
+-
+-        We can still access a::
+-
+-            sage: 2*a
+-            2
+         """
+         # Work around for Singular bug
+         # http://www.singular.uni-kl.de:8002/trac/ticket/727

pkgs/applications/science/math/sage/sage-src.nix

@@ -71,6 +71,9 @@ stdenv.mkDerivation rec {
 
     # fix intermittent errors in sagespawn.pyx: https://trac.sagemath.org/ticket/31052
     ./patches/sagespawn-implicit-casting.patch
+
+    # disable pexpect interrupt test (see https://trac.sagemath.org/ticket/30945)
+    ./patches/disable-pexpect-intermittent-failure.patch
   ];
 
   # Patches needed because of package updates. We could just pin the versions of