sagemath/sage

Meta-ticket: Fix unstable random doctests detected after #29935

kliem opened this issue · 43 comments

kliem commented
  • #32543: Mark unstable tests due do #29956.
  • #32763: Increase tolerance in doctests of modular/modform/numerical.py
  • #33353: increase tolerance of doctests in modular/modform/numerical.py
  • #32771: Fix incorrect doctest introduced in #29978
  • #32772: Fix two random test failures in graphs
  • #32773: Another test failure with KlyachkoBundle_class.random_deformation (duplicate: #32849)
  • #32774: Bug in continue fraction doctest
  • #32783: random doctest failure in src/sage/graphs/generic_graph.py
  • #32816: random doctest failure in rings/polynomial/polynomial_element_generic.py
  • #32817: Fix two tests failing at random
  • #32850: random doctest failure in tests/books/computational-mathematics-with-sagemath/sol/linsolve_doctest.py
  • #32890: Unstable doctest in hmm/chmm.pyx
  • #32891: Unstable doctest geometry/hyperbolic_space/hyperbolic_model.py
  • #32862: Failure in sage/modular/modform/numerical.py for special seed
  • #33015: Random failure in number_field_element.pyx
  • #33035: random doctest failure in src/sage/tests/book_stein_ent.py
  • #33036: random doctest failure in src/sage/crypto/util.py
  • #33039: Random doctest failure in continued_fraction_gosper
  • #33072: Random failure in matrix_gap.pyx
  • #33129: src/sage/plot/plot.py: random doctest failure
  • #33628: random failure in graphs.RandomToleranceGraph
  • #33751: random doctest failure in src/sage/matrix/matrix_integer_dense_hnf.py
  • #33880: Another unstable doctest in hmm/chmm.pyx
  • #34520: remove randomly failing doctest in src/sage/graphs/generators/random.py
  • #34762: fix random chain complex doctest
  • #34901: random doctest failure in src/doc/en/thematic_tutorials/group_theory.rst
  • #32773: random doctest failure in src/sage/schemes/toric/sheaf/klyachko.py

Component: doctest framework

Issue created by migration from https://trac.sagemath.org/ticket/32544

comment:1

I see failures

./sage -t --long --warn-long 101.7 --random-seed=260367842280804525169259077536186393366 src/sage/modular/modform/numerical.py

In detail

Doctesting 1 file.
sage -t --long --warn-long 101.7 --random-seed=260367842280804525169259077536186393366 src/sage/modular/modform/numerical.py
**********************************************************************
File "src/sage/modular/modform/numerical.py", line 74, in sage.modular.modform.numerical.NumericalEigenforms
Failed example:
    n.ap(2)  # rel tol 2e-14
Expected:
    [3.0, -1.6180339887498947, 0.6180339887498968]
Got:
    [3.0, -1.6180339887498947, 0.6180339887498804]
Tolerance exceeded in 1 of 3:
    0.6180339887498968 vs 0.6180339887498804, tolerance 3e-14 > 2e-14
**********************************************************************
File "src/sage/modular/modform/numerical.py", line 76, in sage.modular.modform.numerical.NumericalEigenforms
Failed example:
    n.systems_of_eigenvalues(7)  # rel tol 2e-14
Expected:
    [
    [-1.6180339887498947, 2.2360679774997894, -3.2360679774997894],
    [0.6180339887498968, -2.236067977499788, 1.2360679774997936],
    [3.0, 4.0, 6.0]
    ]
Got:
    [
    [-1.6180339887498947, 2.2360679774997894, -3.2360679774997894],
    [0.6180339887498804, -2.2360679774998293, 1.2360679774997607],
    [3.0, 4.0, 6.0]
    ]
Tolerance exceeded in 2 of 9:
    0.6180339887498968 vs 0.6180339887498804, tolerance 3e-14 > 2e-14
    1.2360679774997936 vs 1.2360679774997607, tolerance 3e-14 > 2e-14
**********************************************************************
File "src/sage/modular/modform/numerical.py", line 88, in sage.modular.modform.numerical.NumericalEigenforms
Failed example:
    n.eigenvalues([2,3,5])  # rel tol 2e-14
Expected:
    [[3.0, -1.6180339887498947, 0.6180339887498968],
     [4.0, 2.2360679774997894, -2.236067977499788],
     [6.0, -3.2360679774997894, 1.2360679774997936]]
Got:
    [[3.0, -1.6180339887498947, 0.6180339887498804],
     [4.0, 2.2360679774997894, -2.2360679774998293],
     [6.0, -3.2360679774997894, 1.2360679774997607]]
Tolerance exceeded in 2 of 9:
    0.6180339887498968 vs 0.6180339887498804, tolerance 3e-14 > 2e-14
    1.2360679774997936 vs 1.2360679774997607, tolerance 3e-14 > 2e-14
**********************************************************************
1 item had failures:
   3 of   7 in sage.modular.modform.numerical.NumericalEigenforms
    [46 tests, 3 failures, 0.26 s]
----------------------------------------------------------------------
sage -t --long --warn-long 101.7 --random-seed=260367842280804525169259077536186393366 src/sage/modular/modform/numerical.py  # 3 doctests failed
kliem commented

Description changed:

--- 
+++ 
@@ -1 +1,2 @@
 - #32543: Mark unstable tests due do #29956.
+- #32763: Increase tolerance in doctests of `modular/modform/numerical.py` 
kliem commented
comment:3
sage -t --long --random-seed=180924489930967511277954046005685261728 src/sage/graphs/base/sparse_graph.pyx
**********************************************************************
File "src/sage/graphs/base/sparse_graph.pyx", line 1163, in sage.graphs.base.sparse_graph._test_adjacency_sequence_out
Failed example:
    _test_adjacency_sequence_out()  # long time
Exception raised:
    Traceback (most recent call last):
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/doctest/forker.py", line 694, in _run
        self.compile_and_execute(example, compiler, test.globs)
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/doctest/forker.py", line 1088, in compile_and_execute
        exec(compiled, globs)
      File "<doctest sage.graphs.base.sparse_graph._test_adjacency_sequence_out[1]>", line 1, in <module>
        _test_adjacency_sequence_out()  # long time
      File "sage/graphs/base/sparse_graph.pyx", line 1189, in sage.graphs.base.sparse_graph._test_adjacency_sequence_out (build/cythonized/sage/graphs/base/sparse_graph.c:9302)
        u = randint(low, n - 1)
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/misc/prandom.py", line 137, in randint
        return _pyrand().randint(a, b)
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/cpython/_py2_random.py", line 220, in randint
        return self.randrange(a, b+1)
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/cpython/_py2_random.py", line 195, in randrange
        raise ValueError("empty range for randrange() (%d,%d, %d)" %
    ValueError: empty range for randrange() (0,0, 0)
sage -t --long --random-seed=180924489930967511277954046005685261728 src/sage/graphs/generators/families.py
**********************************************************************
File "src/sage/graphs/generators/families.py", line 1477, in sage.graphs.generators.families.FriendshipGraph
Failed example:
    G.diameter()
Expected:
    2
Got:
    1
kliem commented
comment:4
sage -t --long --random-seed=23747002002644886606785003174022326205 src/sage/modules/free_module_integer.py
**********************************************************************
File "src/sage/modules/free_module_integer.py", line 370, in sage.modules.free_module_integer.FreeModule_submodule_with_basis_integer.LLL
Failed example:
    new_min <= old_min
Expected:
    True
Got:
    False

sage -t --long --random-seed=23747002002644886606785003174022326205 src/sage/schemes/toric/sheaf/klyachko.py
**********************************************************************
File "src/sage/schemes/toric/sheaf/klyachko.py", line 951, in sage.schemes.toric.sheaf.klyachko.KlyachkoBundle_class.random_deformation
Failed example:
    Vtilde.cohomology(dim=True, weight=(0,))
Expected:
    (1, 0)
Got:
    (0, 0)
kliem commented
comment:5
sage -t --long --random-seed=77478494819088915365500074763386376542 src/sage/rings/continued_fraction.py
**********************************************************************
File "src/sage/rings/continued_fraction.py", line 265, in sage.rings.continued_fraction.rat_interval_cf_list
Failed example:
    for prec in range(10,54):
        R = RealIntervalField(20)
        for _ in range(100):
            x = R.random_element() * R.random_element() + R.random_element() / 100
            l = x.lower().exact_rational()
            u = x.upper().exact_rational()
            cf = rat_interval_cf_list(l,u)
            a = continued_fraction(cf).value()
            b = continued_fraction(cf+[1]).value()
            if a > b:
                a,b = b,a
            assert a <= l
            assert b >= u
Exception raised:
    Traceback (most recent call last):
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/doctest/forker.py", line 694, in _run
        self.compile_and_execute(example, compiler, test.globs)
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/doctest/forker.py", line 1088, in compile_and_execute
        exec(compiled, globs)
      File "<doctest sage.rings.continued_fraction.rat_interval_cf_list[2]>", line 8, in <module>
        a = continued_fraction(cf).value()
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/rings/continued_fraction.py", line 2625, in continued_fraction
        x1, x2 = check_and_reduce_pair(x)
      File "/home/jonathan/Applications/sage/local/lib/python3.8/site-packages/sage/rings/continued_fraction.py", line 2254, in check_and_reduce_pair
        raise ValueError("continued fraction can not represent infinity")
    ValueError: continued fraction can not represent infinity
**********************************************************************
1 item had failures:
   1 of   4 in sage.rings.continued_fraction.rat_interval_cf_list
    [437 tests, 1 failure, 5.09 s]
-------------------------------------------------------------
kliem commented
comment:6

Created tickets for reported failures so far.

kliem commented

Description changed:

--- 
+++ 
@@ -1,2 +1,6 @@
 - #32543: Mark unstable tests due do #29956.
-- #32763: Increase tolerance in doctests of `modular/modform/numerical.py` 
+- #32763: Increase tolerance in doctests of `modular/modform/numerical.py`
+- #32771: Fix incorrect doctest introduced in #29978 
+- #32772: Fix two random test failures in graphs 
+- #32773: Another test failure with KlyachkoBundle_class.random_deformation  
+- #32774: Bug in continue fraction doctest 

Description changed:

--- 
+++ 
@@ -4,3 +4,5 @@
 - #32772: Fix two random test failures in graphs 
 - #32773: Another test failure with KlyachkoBundle_class.random_deformation  
 - #32774: Bug in continue fraction doctest 
+- #32783: random doctest failure in `src/sage/graphs/generic_graph.py`
+
comment:8

Seen in https://patchbot.sagemath.org/log/32777/Linux/1_SMP_Debian_5.10.70-1_(2021-09-30)/x86_64/5.10.0-9-amd64/tmonteil-lxc1/2021-10-27%2001:20:12

sage -t --long --random-seed=321172385432269463934777057410284981568 src/sage/rings/polynomial/multi_polynomial_ring_base.pyx
**********************************************************************
File "src/sage/rings/polynomial/multi_polynomial_ring_base.pyx", line 994, in sage.rings.polynomial.multi_polynomial_ring_base.MPolynomialRing_base.random_element
Failed example:
    len(list(f))
Expected:
    1
Got:
    0
comment:9

From https://patchbot.sagemath.org/log/32762/Linux/1_SMP_Debian_5.10.70-1_(2021-09-30)/x86_64/5.10.0-9-amd64/tmonteil-lxc1/2021-10-25%2015:13:58

sage -t --long --random-seed=324642231642420052385517156149041216749 src/sage/dynamics/arithmetic_dynamics/projective_ds.py
**********************************************************************
File "src/sage/dynamics/arithmetic_dynamics/projective_ds.py", line 7076, in sage.dynamics.arithmetic_dynamics.projective_ds.?.conjugating_set
Failed example:
    D6.conjugating_set(D6)
Expected:
    [
    [1 0]  [0 1]  [0 2]  [4 0]  [2 0]  [0 4]
    [0 1], [1 0], [1 0], [0 1], [0 1], [1 0]
    ]
Got:
    [
    [4 0]  [2 0]  [0 4]  [1 0]  [0 1]  [0 2]
    [0 1], [0 1], [1 0], [0 1], [1 0], [1 0]
    ]

Description changed:

--- 
+++ 
@@ -5,4 +5,4 @@
 - #32773: Another test failure with KlyachkoBundle_class.random_deformation  
 - #32774: Bug in continue fraction doctest 
 - #32783: random doctest failure in `src/sage/graphs/generic_graph.py`
-
+- #32816: random doctest failure in rings/polynomial/polynomial_element_generic.py
kliem commented

Description changed:

--- 
+++ 
@@ -6,3 +6,4 @@
 - #32774: Bug in continue fraction doctest 
 - #32783: random doctest failure in `src/sage/graphs/generic_graph.py`
 - #32816: random doctest failure in rings/polynomial/polynomial_element_generic.py
+-  #32817: Fix two tests failing at random 
kliem commented
comment:11

Created tickets for reported failures so far.

Description changed:

--- 
+++ 
@@ -5,5 +5,7 @@
 - #32773: Another test failure with KlyachkoBundle_class.random_deformation  
 - #32774: Bug in continue fraction doctest 
 - #32783: random doctest failure in `src/sage/graphs/generic_graph.py`
-- #32816: random doctest failure in rings/polynomial/polynomial_element_generic.py
--  #32817: Fix two tests failing at random 
+- #32816: random doctest failure in `rings/polynomial/polynomial_element_generic.py`
+- #32817: Fix two tests failing at random 
+- #32849: random doctest failure in `schemes/toric/sheaf/klyachko.py`
+- #32850: random doctest failure in `tests/books/computational-mathematics-with-sagemath/sol/linsolve_doctest.py`

Description changed:

--- 
+++ 
@@ -2,10 +2,9 @@
 - #32763: Increase tolerance in doctests of `modular/modform/numerical.py`
 - #32771: Fix incorrect doctest introduced in #29978 
 - #32772: Fix two random test failures in graphs 
-- #32773: Another test failure with KlyachkoBundle_class.random_deformation  
+- #32773: Another test failure with KlyachkoBundle_class.random_deformation (duplicate: #32849)
 - #32774: Bug in continue fraction doctest 
 - #32783: random doctest failure in `src/sage/graphs/generic_graph.py`
 - #32816: random doctest failure in `rings/polynomial/polynomial_element_generic.py`
 - #32817: Fix two tests failing at random 
-- #32849: random doctest failure in `schemes/toric/sheaf/klyachko.py`
 - #32850: random doctest failure in `tests/books/computational-mathematics-with-sagemath/sol/linsolve_doctest.py`
kliem commented

Description changed:

--- 
+++ 
@@ -8,3 +8,4 @@
 - #32816: random doctest failure in `rings/polynomial/polynomial_element_generic.py`
 - #32817: Fix two tests failing at random 
 - #32850: random doctest failure in `tests/books/computational-mathematics-with-sagemath/sol/linsolve_doctest.py`
+-  #32890: Unstable doctest in hmm/chmm.pyx 
kliem commented

Description changed:

--- 
+++ 
@@ -9,3 +9,4 @@
 - #32817: Fix two tests failing at random 
 - #32850: random doctest failure in `tests/books/computational-mathematics-with-sagemath/sol/linsolve_doctest.py`
 -  #32890: Unstable doctest in hmm/chmm.pyx 
+-  #32891: Unstable doctest geometry/hyperbolic_space/hyperbolic_model.py 
kliem commented

Description changed:

--- 
+++ 
@@ -10,3 +10,4 @@
 - #32850: random doctest failure in `tests/books/computational-mathematics-with-sagemath/sol/linsolve_doctest.py`
 -  #32890: Unstable doctest in hmm/chmm.pyx 
 -  #32891: Unstable doctest geometry/hyperbolic_space/hyperbolic_model.py 
+-  #32862: Failure in sage/modular/modform/numerical.py for special seed 
kliem commented

Description changed:

--- 
+++ 
@@ -10,4 +10,5 @@
 - #32850: random doctest failure in `tests/books/computational-mathematics-with-sagemath/sol/linsolve_doctest.py`
 -  #32890: Unstable doctest in hmm/chmm.pyx 
 -  #32891: Unstable doctest geometry/hyperbolic_space/hyperbolic_model.py 
--  #32862: Failure in sage/modular/modform/numerical.py for special seed 
+-  #32862: Failure in sage/modular/modform/numerical.py for special seed
+-  #33015: Random failure in number_field_element.pyx  

Description changed:

--- 
+++ 
@@ -12,3 +12,4 @@
 -  #32891: Unstable doctest geometry/hyperbolic_space/hyperbolic_model.py 
 -  #32862: Failure in sage/modular/modform/numerical.py for special seed
 -  #33015: Random failure in number_field_element.pyx  
+-  #33035: random doctest failure in `src/sage/tests/book_stein_ent.py`

Description changed:

--- 
+++ 
@@ -13,3 +13,4 @@
 -  #32862: Failure in sage/modular/modform/numerical.py for special seed
 -  #33015: Random failure in number_field_element.pyx  
 -  #33035: random doctest failure in `src/sage/tests/book_stein_ent.py`
+-  #33036: random doctest failure in `src/sage/crypto/util.py`
kliem commented

Description changed:

--- 
+++ 
@@ -14,3 +14,4 @@
 -  #33015: Random failure in number_field_element.pyx  
 -  #33035: random doctest failure in `src/sage/tests/book_stein_ent.py`
 -  #33036: random doctest failure in `src/sage/crypto/util.py`
+-  #33039: Random doctest failure in continued_fraction_gosper 

Description changed:

--- 
+++ 
@@ -14,4 +14,5 @@
 -  #33015: Random failure in number_field_element.pyx  
 -  #33035: random doctest failure in `src/sage/tests/book_stein_ent.py`
 -  #33036: random doctest failure in `src/sage/crypto/util.py`
--  #33039: Random doctest failure in continued_fraction_gosper 
+-  #33039: Random doctest failure in continued_fraction_gosper
+-  #33072: Random failure in matrix_gap.pyx
comment:23

bump to 9.6

Description changed:

--- 
+++ 
@@ -1,5 +1,6 @@
 - #32543: Mark unstable tests due do #29956.
 - #32763: Increase tolerance in doctests of `modular/modform/numerical.py`
+- #33353: increase tolerance of doctests in `modular/modform/numerical.py`
 - #32771: Fix incorrect doctest introduced in #29978 
 - #32772: Fix two random test failures in graphs 
 - #32773: Another test failure with KlyachkoBundle_class.random_deformation (duplicate: #32849)

Description changed:

--- 
+++ 
@@ -17,3 +17,4 @@
 -  #33036: random doctest failure in `src/sage/crypto/util.py`
 -  #33039: Random doctest failure in continued_fraction_gosper
 -  #33072: Random failure in matrix_gap.pyx
+-  #33628: random failure in `graphs.RandomToleranceGraph`

Description changed:

--- 
+++ 
@@ -18,3 +18,4 @@
 -  #33039: Random doctest failure in continued_fraction_gosper
 -  #33072: Random failure in matrix_gap.pyx
 -  #33628: random failure in `graphs.RandomToleranceGraph`
+-  #33751: random doctest failure in `src/sage/matrix/matrix_integer_dense_hnf.py`

Description changed:

--- 
+++ 
@@ -19,3 +19,5 @@
 -  #33072: Random failure in matrix_gap.pyx
 -  #33628: random failure in `graphs.RandomToleranceGraph`
 -  #33751: random doctest failure in `src/sage/matrix/matrix_integer_dense_hnf.py`
+- #33880: Another unstable doctest in `hmm/chmm.pyx`
+
comment:29

2 random errors with 9.7.beta5 (both macOS and fedora):

sage -t --long --random-seed=224943010850339078223674527953664126031 src/sage/plot/plot.py
**********************************************************************
File "src/sage/plot/plot.py", line 1819, in sage.plot.plot.plot
Failed example:
    plot(f, (x, -3.5, 3.5), detect_poles='show', exclude=[-3..3], ymin=-5, ymax=5)
Expected:
    Graphics object consisting of 12 graphics primitives
Got:
    Graphics object consisting of 13 graphics primitives

and

sage -t --long --random-seed=224943010850339078223674527953664126031 src/sage/schemes/toric/sheaf/klyachko.py
**********************************************************************
File "src/sage/schemes/toric/sheaf/klyachko.py", line 951, in sage.schemes.toric.sheaf.klyachko.KlyachkoBundle_class.random_deformation
Failed example:
    Vtilde.cohomology(dim=True, weight=(0,))
Expected:
    (1, 0)
Got:
    (0, 0)
comment:30

The failures in comment:29 already have tickets: the plot failure is #33129 and the Vtilde.cohomology failure is #32773 (which is already in the ticket description). So I added #33129 to the ticket description.

Description changed:

--- 
+++ 
@@ -17,6 +17,7 @@
 -  #33036: random doctest failure in `src/sage/crypto/util.py`
 -  #33039: Random doctest failure in continued_fraction_gosper
 -  #33072: Random failure in matrix_gap.pyx
+-  #33129: src/sage/plot/plot.py: random doctest failure
 -  #33628: random failure in `graphs.RandomToleranceGraph`
 -  #33751: random doctest failure in `src/sage/matrix/matrix_integer_dense_hnf.py`
 - #33880: Another unstable doctest in `hmm/chmm.pyx`
comment:31
sage -t --random-seed=124699541928353137721504742146487601068 src/sage/graphs/generators/random.py
**********************************************************************
File "src/sage/graphs/generators/random.py", line 817, in sage.graphs.generators.random.RandomHolmeKim
Failed example:
    G.subgraph_search(C3)
Expected:
    Subgraph of (): Graph on 3 vertices
Got:
    <BLANKLINE>
**********************************************************************
1 item had failures:
   1 of   6 in sage.graphs.generators.random.RandomHolmeKim
    [197 tests, 1 failure, 1.92 s]
comment:32

This doctest checks for the existence of a triangle in graphs.RandomHolmeKim(8, 2, 0.5). To reduce the probability of getting a triangle free graph, we can go for a larger graph, or simply mark this test as random.

comment:33

It's fine with me to mark this test as random, but I think it might be better to delete it, because it doesn't seem to be providing a very meaningful test of the Holme-Kim algorithm. (I am -1 on enlarging the graph or increasing the probability of triangle-formation.) Even if 0.5 is changed to 0 (which I think means that the triangle-formation step is being skipped), the graph still has at least one triangle with high probability.

sage: count = sum(graphs.RandomHolmeKim(8, 2, 0).triangles_count() > 0 for _ in range(1000))
sage: print(f"{round(count/10,1)}% of the graphs have at least one triangle")
99.1% of the graphs have at least one triangle
sage: [graphs.RandomHolmeKim(8, 2, 0).triangles_count() for _ in range(10)]
[4, 4, 3, 4, 3, 4, 3, 2, 2, 3]

Ideally, we would have a better test that the algorithm is working correctly, but I don't have any suggestions.

Description changed:

--- 
+++ 
@@ -21,4 +21,5 @@
 -  #33628: random failure in `graphs.RandomToleranceGraph`
 -  #33751: random doctest failure in `src/sage/matrix/matrix_integer_dense_hnf.py`
 - #33880: Another unstable doctest in `hmm/chmm.pyx`
+- #34520: remove randomly failing doctest in `src/sage/graphs/generators/random.py`
 
comment:34

I opened #34520. I agree that it's better to completely remove the doctest and I don't have better tests in mind yet.

comment:36

with sage 9.8.beta3

sage -t --long --warn-long 41.8 --random-seed=133497414867200611466007568756298202280 src/sage/homology/tests.py
**********************************************************************
File "src/sage/homology/tests.py", line 50, in sage.homology.tests.random_chain_complex
Failed example:
    C
Expected:
    Chain complex with at most ... nonzero terms over Integer Ring
Got:
    Trivial chain complex over Integer Ring
**********************************************************************
File "src/sage/homology/tests.py", line 52, in sage.homology.tests.random_chain_complex
Failed example:
    len(C.nonzero_degrees()) in [1, 2]
Expected:
    True
Got:
    False
**********************************************************************

Description changed:

--- 
+++ 
@@ -22,4 +22,4 @@
 -  #33751: random doctest failure in `src/sage/matrix/matrix_integer_dense_hnf.py`
 - #33880: Another unstable doctest in `hmm/chmm.pyx`
 - #34520: remove randomly failing doctest in `src/sage/graphs/generators/random.py`
-
+- #34762: fix random chain complex doctest
comment:37

Replying to David Coudert:

with sage 9.8.beta3

sage -t --long --warn-long 41.8 --random-seed=133497414867200611466007568756298202280 src/sage/homology/tests.py
**********************************************************************
File "src/sage/homology/tests.py", line 50, in sage.homology.tests.random_chain_complex
Failed example:
    C
Expected:
    Chain complex with at most ... nonzero terms over Integer Ring
Got:
    Trivial chain complex over Integer Ring
**********************************************************************
File "src/sage/homology/tests.py", line 52, in sage.homology.tests.random_chain_complex
Failed example:
    len(C.nonzero_degrees()) in [1, 2]
Expected:
    True
Got:
    False
**********************************************************************

I have a fix in #34762.

Description changed:

--- 
+++ 
@@ -23,3 +23,5 @@
 - #33880: Another unstable doctest in `hmm/chmm.pyx`
 - #34520: remove randomly failing doctest in `src/sage/graphs/generators/random.py`
 - #34762: fix random chain complex doctest
+- #34901: random doctest failure in `src/doc/en/thematic_tutorials/group_theory.rst`
+

Description changed:

--- 
+++ 
@@ -24,4 +24,5 @@
 - #34520: remove randomly failing doctest in `src/sage/graphs/generators/random.py`
 - #34762: fix random chain complex doctest
 - #34901: random doctest failure in `src/doc/en/thematic_tutorials/group_theory.rst`
+- #34914: random doctest failure in `src/sage/schemes/toric/sheaf/klyachko.py`
 

Description changed:

--- 
+++ 
@@ -24,5 +24,5 @@
 - #34520: remove randomly failing doctest in `src/sage/graphs/generators/random.py`
 - #34762: fix random chain complex doctest
 - #34901: random doctest failure in `src/doc/en/thematic_tutorials/group_theory.rst`
-- #34914: random doctest failure in `src/sage/schemes/toric/sheaf/klyachko.py`
+- #32773: random doctest failure in `src/sage/schemes/toric/sheaf/klyachko.py`