# Why --optional=sage,optional,external does not test internet,graphviz,latex,gurobi ?

When running tests with `--optional=sage,optional,external`

```
$ sage -t --show-skipped --optional=sage,optional,external src/sage/graphs/graph_latex.py src/sage/databases/oeis.py src/sage/numerical/mip.pyx src/sage/misc/latex.py
```

the tests with labels `latex`

,`gurobi`

, `graphviz`

, `internet`

are skipped even if `latex`

,`gurobi`

, `graphviz`

, `internet`

are installed on my machine:

```
Running doctests with ID 2018-05-06-10-12-34-1494f13d.
Using --optional=ccache,dot2tex,external,mpir,notedown,pandoc_attributes,python2,rst2ipynb,sage
External software to be detected: cplex,gurobi,internet,latex,macaulay2,magma,maple,mathematica,matlab,octave,scilab
Doctesting 4 files.
sage -t src/sage/graphs/graph_latex.py
4 graphviz tests not run
[187 tests, 1.08 s]
sage -t src/sage/databases/oeis.py
150 internet tests not run
5 webbrowser tests not run
[118 tests, 2.28 s]
sage -t src/sage/numerical/mip.pyx
8 cplex tests not run
3 gurobi tests not run
7 other tests skipped
[616 tests, 3.69 s]
sage -t src/sage/misc/latex.py
1 imagemagick test not run
5 latex tests not run
3 other tests skipped
[315 tests, 3.00 s]
----------------------------------------------------------------------
All tests passed!
----------------------------------------------------------------------
Total time for all tests: 11.1 seconds
cpu time: 7.5 seconds
cumulative wall time: 10.1 seconds
External software detected for doctesting: gurobi,latex
```

Detecting

`internet`

capabilities is broken: see https://trac.sagemath.org/ticket/25222. To test`latex`

, for example, use these commands:`from sage.doctest.external import has_latex`

and then`has_latex()`

. It should return`True`

.Also, maybe doctesting is broken: even if software is detected (like

`latex`

in your case), maybe it's not used in testing.`has_internet`

is broken indeed but the other two are not:So there seems to be also a problem in doctesting.

adding

`has_graphviz`

now needs review at https://trac.sagemath.org/ticket/25305And I just figured out that "5 latex tests not run" does not mean they are not run!! https://trac.sagemath.org/ticket/25308 needs review