TLSH is a fuzzy matching library. Given a byte stream with a minimum
length of 256 bytes, TLSH generates a hash value which can be used for
similarity comparisons.

("TLSH" stands for Trend Micro Locality Sensitive Hash.)

python3 is an optional dependency.  You need to set PYTHON3=yes,
for example:

  PYTHON3=yes ./python-libarchive-c.SlackBuild