detect resolution interdependencies

[n2ygk]

I'm not sure this can even be figured out by pur, but when I ran it against my requirements and then did a pip install this dependency error happened. I have to say it's not a big deal to manually fix these but an automated detection of this kind of dependency conflict would be great!

INFO: pip is looking at multiple versions of arrow to determine which version is compatible with other requirements. This could take a while.
ERROR: Cannot install -r requirements.txt (line 17) and arrow==0.17.0 because these package versions have conflicting dependencies.

The conflict is caused by:
    The user requested arrow==0.17.0
    ics 0.7 depends on arrow<0.15 and >=0.11

To fix this you could try to:
1. loosen the range of package versions you've specified
2. remove package versions to allow pip attempt to solve the dependency conflict

ERROR: ResolutionImpossible: for help visit https://pip.pypa.io/en/latest/user_guide/#fixing-conflicting-dependencies

and then after manually fixing that:

ERROR: Cannot install -r requirements.txt (line 37) and idna==3.1 because these package versions have conflicting dependencies.

The conflict is caused by:
    The user requested idna==3.1
    requests 2.25.1 depends on idna<3 and >=2.5

To fix this you could try to:
1. loosen the range of package versions you've specified
2. remove package versions to allow pip attempt to solve the dependency conflict

ERROR: ResolutionImpossible: for help visit https://pip.pypa.io/en/latest/user_guide/#fixing-conflicting-dependencies

Manually fixing that got me up to date with those two exceptions which is way better than the old way of pinning versions once and then never updating!