How to protect installations from being modified by other packages

One way to do this is to use watch. If you do 
watch('myDirectory')
for example, Pacman will absorb the directory tree myDirectory/... into the environment that it watches over. The 'time' argument means that Pacman will save the time stamps of all the files in the tree. In this case, when an installer does 
 % pacman -verify
Pacman will check that none of the files have been modified.

In Pacman, if your package environment needs package Foo and you want to be sure that your package will be re-installed if Foo ever changes, the normal thing do do is 

 % configure('Foo')
If "Foo" is, on the other hand, non-Pacman installed software, you can do something similar by using watch to absorb the contents of Foo into your environment.

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