Packages should be saved in an All directory.
# pkg create -o ./ -f tgz pkg-1.3.6
Creating package for pkg-1.3.6
# ls
pkg-1.3.6.tgz
# pkg repo .
pkg: No package files have been found
Cannot create repository catalogue
# pkg create -o ./ -f txz pkg-1.3.6
Creating package for pkg-1.3.6
# ls
pkg-1.3.6.txz
# pkg repo .
Creating repository in .: 100%
Packing files for repository: 100%
#
# time pkg create -o ./ -f txz pkg-1.3.6
Creating package for pkg-1.3.6
real 0m14.729s
user 0m13.769s
sys 0m0.788s
# time pkg create -o ./ -f tgz pkg-1.3.6
Creating package for pkg-1.3.6
real 0m2.117s
user 0m1.974s
sys 0m0.025s