Compare session information from two sources

Usage

session_diff(
  old = "local",
  new = "clipboard",
  packages = c("diff", "merge"),
  ...
)

old, new

A session_info object (the return value of session_info()), or a pointer to session_info() output. See details below.

packages

How to compare the package info for old and new:

"diff": line diffs, in the style of diff -u
"merge": merge the information into one data frame, with one row per package. Only package version and source are compared.

...

Passed to any new session_info() calls.

Various way to specify old and new:

A session_info object.
"local" runs session_info() in the current session, and uses its output.
"clipboard" takes the session info from the system clipboard. If the clipboard contains a URL, it is followed to download the session info.
The URL where you inspect the results for a GitHub Actions job. Typically has this form:
```
https://github.com/OWNER/REPO/actions/runs/RUN_ID/jobs/HTML_ID
```
Internally, this URL is parsed so we can look up the job id, get the log file, and extract session info.
Any other URL starting with http:// or https://. session_diff() searches the HTML (or text) page for the session info header to find the session info.

if (FALSE) {
session_diff()
}