chicken-install -s should not use sudo if it is not necessary

[Christian Kellermann]

Currently chicken-install -s unconditionally invokes sudo which installs eggs with root permissions even in the case of local installs, i.e. in your own home directory.

I would expect it to be smarter and use only sudo if the current permissions aren't enough to install an egg.

[Shawn Rutledge]

That would be a nice feature. Or maybe chicken-install could automatically do that even without the -s parameter, only if current permissions are not enough. It could ask first, but sudo already involves asking first unless sudo was run recently.

The issue is that a regular Linux user getting chicken from distro packages will have chicken in /usr/bin, but (s)he will not necessarily have all the eggs from distro packages. It's nice to be able to run chicken-install as a normal user. As an egg developer, I do chmod a+w /usr/lib/chicken/7 so that I can install my own eggs frequently. So I don't want to have a pattern of requiring root permission to install every egg, but there are a few that install tools in /usr/bin (chicken-doc and chicken-wrap for example), and that is the only case when I would like chicken-install to use sudo.