2 failing doctests in sql_db.py

[seblabbe]

As mentionned earlier in sage-release of 8.5.beta5, runing Ubuntu 16.04, with

$ sage --version
SageMath version 8.5.rc0, Release Date: 2018-12-10

the command

sage -t src/sage/databases/sql_db.py 

gives

Git branch: develop
Using --optional=bliss,cbc,ccache,cmake,dochtml,dot2tex,gmpy2,lrslib,memlimit,mpir,normaliz,notedown,pandoc_attributes,pycosat,pynormaliz,python2,rst2ipynb,sage
Doctesting 1 file.
sage -t src/sage/databases/sql_db.py
**********************************************************************
File "src/sage/databases/sql_db.py", line 956, in sage.databases.sql_db.SQLDatabase.__init__
Failed example:
    D.show('simon')
Expected:
    graph6               vertices             edges
    ------------------------------------------------------------
    ?                    0                    0
    @                    1                    0
    A?                   2                    0
    A_                   2                    1
    B?                   3                    0
    BG                   3                    1
    BW                   3                    2
    Bw                   3                    3
    C?                   4                    0
    C@                   4                    1
    CB                   4                    2
    CF                   4                    3
    CJ                   4                    3
    CK                   4                    2
    CL                   4                    3
    CN                   4                    4
    C]                   4                    4
    C^                   4                    5
    C~                   4                    6
Got:
    graph6               vertices             edges               
    ------------------------------------------------------------
    ?                    0                    0                   
    @                    1                    0                   
    A?                   2                    0                   
    A_                   2                    1                   
    B?                   3                    0                   
    BG                   3                    1                   
    BW                   3                    2                   
    Bw                   3                    3                   
    C?                   4                    0                   
    C@                   4                    1                   
    CB                   4                    2                   
    CF                   4                    3                   
    CJ                   4                    3                   
    C`                   4                    2                   
    CR                   4                    3                   
    CN                   4                    4                   
    Cr                   4                    4                   
    C^                   4                    5                   
    C~                   4                    6                   
**********************************************************************
File "src/sage/databases/sql_db.py", line 1004, in sage.databases.sql_db.SQLDatabase.__init__
Failed example:
    E.show('simon')
Expected:
    graph6               vertices             edges
    ------------------------------------------------------------
    ?                    0                    0
    @                    1                    0
    A?                   2                    0
    A_                   2                    1
    B?                   3                    0
    BG                   3                    1
    BW                   3                    2
    Bw                   3                    3
    C?                   4                    0
    C@                   4                    1
    CB                   4                    2
    CF                   4                    3
    CJ                   4                    3
    CK                   4                    2
    CL                   4                    3
    CN                   4                    4
    C]                   4                    4
    C^                   4                    5
    C~                   4                    6
Got:
    graph6               vertices             edges               
    ------------------------------------------------------------
    ?                    0                    0                   
    @                    1                    0                   
    A?                   2                    0                   
    A_                   2                    1                   
    B?                   3                    0                   
    BG                   3                    1                   
    BW                   3                    2                   
    Bw                   3                    3                   
    C?                   4                    0                   
    C@                   4                    1                   
    CB                   4                    2                   
    CF                   4                    3                   
    CJ                   4                    3                   
    C`                   4                    2                   
    CR                   4                    3                   
    CN                   4                    4                   
    Cr                   4                    4                   
    C^                   4                    5                   
    C~                   4                    6                   
**********************************************************************
1 item had failures:
   2 of  26 in sage.databases.sql_db.SQLDatabase.__init__
    [288 tests, 2 failures, 1.56 s]
----------------------------------------------------------------------
sage -t src/sage/databases/sql_db.py  # 2 doctests failed
----------------------------------------------------------------------

CC: @antonio-rojas

Component: doctest coverage

Issue created by migration from https://trac.sagemath.org/ticket/26920

[seblabbe]

comment:3

Another ticket has been opened to deal with the same issue: #26994. I suggest to close this one here as a duplicate since the other ticket is more advanced on understanding the issue (the issue seems related to the installation of optional package bliss).