For the "ferret" package, I use hg to clone the repository. But hg may not be installed.
Possible solutions:
Do not use hg in ferret and elsewhere.
Add a hg package.
Make the package optional; i.e. when trying to build ferret w/o hg present, print a friendly and helpful error message, but let the build continue otherwise.
For the "ferret" package, I use hg to clone the repository. But hg may not be installed.
Possible solutions: