Lesspipe detects feature availability in two steps:

1. ./configure detects which helper programs (unzip, html2text, mp3info...) are present on the computer and creates a lesspipe.sh file that only contains those.
2. when lesspipe.sh a certain file type, it checks for the particular helper program's presence.

So, for example, for viewing RTF files to work the user has to have unrtf installed AND the package builder has to have it too. Because of this, lesspipe 1.70-2, the current build, has a lot less features than it could have. (For example, mp3info support is missing.)

To fix it, change
./configure --prefix=/usr --default
to
./configure --prefix=/usr --yes
This means ./configure assumes everything is present and creates a full-featured lesspipe.sh. If a program is missing, lesspipe.sh falls back gracefully. ("filename may be a binary file. See it anyway?")

Additional info:
* lesspipe 1.70-2

Steps to reproduce:
* with lesspipe and mp3info installed and working, less some_mp3_file.mp3.
* binary data is shown instead of human readable meta-data.