PEP 610: Recording the origin of distributions installed from direct URL references

A few questions:

  1. if I run pip install . in several projects it would not be very useful to have "url": "." in the direct_url.json. One approach could be to canonicalize the url and store it in this field. Another could be to store the requested ref and context separately e.g. {"url": ".", "url-context": "/home/user/pkg"}. Has this already been discussed?
  2. Given that, must we specify “relative ref” path interpretation expectations for tools or separate the action somehow? Currently these seem under-specified (related discussion here).
  3. I didn’t see any encoding mentioned for direct_url.json. RFC 8259 has a few words about it in 8.1 (i.e. MUST be encoded using UTF-8). Is that enough or do we want to mention it explicitly?