This repository is fetched by r2pm -U
and provides the package database.
These packages are installed in user's home and can be plugins/scripts for radare2 or even utilities/programs related to r2.
See https://github.com/radareorg/radare2 for r2pm
$ r2pm -U
$ r2pm -ci r2frida
export R2PM_DBDIR="$PWD/db"
# export R2PM_GITDIR="/path/to/the/root/folder/of/the/local/repository"
# export R2PM_USRDIR="/path/to/usr/dir"