Principles

A good error message should mention:

• what the user has tried to do
• possible next steps to try and solve the error
  • possible steps need to go from "easiest" to "most complicated"
• why the error has happened - see more information about the situation

In the case of pip error messages, they should also provide:

• reason(s) why the error occured

Further reading

https://uxplanet.org/how-to-write-good-error-messages-858e4551cd4

https://www.nngroup.com/articles/error-message-guidelines/

Error message format

We propose pip resolver error messages have 3 parts -

• what the error is (i.e. what the user has tried to do)
• what has caused the error
• possible ways to solve the error

resolution:impossible

where a user wants to install packages (with 1 or more pinned version)

with default verbose level