There was no user interface, and the feature that it provides has lost
relevance over time.
Note that algorithms for block and/or bytecode still internally use some
equivalent of this parameter, but its initial value will no longer be
modifiable (which could lead to bugs, see commit
e49e7e906f).
With stack_solve_algo={0, 6} the verbosity is controlled with
options_.verbosity instead of options_.no_homotopy.
Also harmonized the printed informations across these two algorithms.
Sébastien Villemot
Stéphane Adjemian (Charybdis)
Houtan Bastani