suppose the following packages: a, b, c, d
with the following dependency relationships between their versioned distributions
-
a-1
-
b
-
c-1
-
c-1
- d-1
-
a-2
- b
- c-2
-
c-2
- d-2
and suppose the following distributions are available on the index: a-1, a-2, b-1, b-2, c-1, c-2, d-1, d-2
let's do the following in a virtualenv:
pip install b==1
pip install a==1
pip freeze
you'll have this:
a==1
b==1
c==1
d==1
now do this:
pip install -U --no-deps a
pip freeze
you'll have this:
a==2
b==1
c==1
d==1
now do this:
pip install a
pip freeze
you'll have this:
a==2
b==1
c==2
d==2
c and d are upgraded to fulfill requirements, but b is not upgraded.