LeveshteinSimilarityIndex fails when called from SparseTermSimilarityMatrix

[ptorrestr]

Problem description

When trying to build a SparseTermSimilarityMatrix using Levenshtein it fails.

Steps/code/corpus to reproduce

index = LevenshteinSimilarityIndex(dictionary)
SparseTermSimilarityMatrix(index, dictionary) # <- fails here

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-59-c16b89564835> in <module>
----> 1 similarity_matrix1 = SparseTermSimilarityMatrix(similarity_index1, dictionary)

~/.local/share/virtualenvs/pdftagger-LHy_2RHk/lib/python3.6/site-packages/gensim/similarities/termsim.py in __init__(self, source, dictionary, tfidf, symmetric, positive_definite, nonzero_limit, dtype)
    234                 for term, similarity in index.most_similar(t1, topn=num_rows)
    235                 if term in dictionary.token2id
--> 236             ] if num_rows > 0 else []
    237 
    238             if tfidf is None:

~/.local/share/virtualenvs/pdftagger-LHy_2RHk/lib/python3.6/site-packages/gensim/similarities/levenshtein.py in most_similar(self, t1, topn)
    151             if similarity > 0
    152         )
--> 153         return islice(most_similar, topn)

ValueError: Stop argument for islice() must be None or an integer: 0 <= x <= sys.maxsize.

Versions

Linux-4.18.0-25-generic-x86_64-with-debian-buster-sid
Python 3.6.9 (default, Nov 18 2019, 15:20:23)
[GCC 8.3.0]
NumPy 1.17.4
SciPy 1.3.3
gensim 3.8.1
FAST_VERSION 1