Fricas testdoc fails in 8.2.beta1

[charpent]

As reported in ​sage-release, I get a testdoc failure for fricas with 8.2.beta1 :

charpent@asus16-ec:/usr/local/sage-8$ sage -t --long src/sage/interfaces/fricas.py
too many failed tests, not using stored timings
Running doctests with ID 2017-12-26-08-08-36-f9785428.
Git branch: 82beta1R343
Using --optional=database_gap,dot2tex,fricas,giacpy_sage,igraph,mpir,python2,python_igraph,sage
Doctesting 1 file.
sage -t --long src/sage/interfaces/fricas.py
**********************************************************************
File "src/sage/interfaces/fricas.py", line 1097, in sage.interfaces.fricas.FriCASElement._sage_expression
Failed example:
    [f(x)._fricas_().sage().subs(x=0.9) for f in l]               # optional - fricas
Expected:
    [0.716297870199024,
     1.02651672570818,
     1.43308638544877,
     1.39606725303001,
     0.697794641100332,
     0.974168247780004,
     0.808866935652782,
     NaN,
     1.47221948958322,
     NaN,
     0.467145308103262,
     0.957800449200672,
     0.808866935652782,
     NaN,
     1.47221948958322,
     NaN,
     0.467145308103262,
     0.957800449200672]
Got:
    [0.716297870199024,
     1.02651672570818,
     1.43308638544877,
     1.39606725303001,
     0.697794641100332,
     0.974168247780004,
     0.808866935652782,
     0.451026811796262*I,
     1.47221948958322,
     1.47221948958322,
     0.467145308103262,
     0.957800449200672,
     0.808866935652782,
     0.451026811796262*I,
     1.47221948958322,
     1.47221948958322,
     0.467145308103262,
     0.957800449200672]
**********************************************************************
1 item had failures:
   1 of  10 in sage.interfaces.fricas.FriCASElement._sage_expression
    [173 tests, 1 failure, 19.68 s]
----------------------------------------------------------------------
sage -t --long src/sage/interfaces/fricas.py  # 1 doctest failed
----------------------------------------------------------------------
Total time for all tests: 24.8 seconds
    cpu time: 1.7 seconds
    cumulative wall time: 19.7 seconds

For niow, I have no idea of the reason for tghis, but I tghink important to report it for the record.

[mantepse]

This is #24426 (and has nothing to do with FriCAS)