A `spack diff` will take two specs, and then use the spack.solver.asp.SpackSolverSetup to generate
lists of facts about each (e.g., nodes, variants, etc.) and then take a set difference between the
two to show the user the differences.
Example output:
$ spack diff python@2.7.8 python@3.8.11
==> Warning: This interface is subject to change.
--- python@2.7.8/tsxdi6gl4lihp25qrm4d6nys3nypufbf
+++ python@3.8.11/yjtseru4nbpllbaxb46q7wfkyxbuvzxx
@@ variant_value @@
- python patches a8c52415a8b03c0e5f28b5d52ae498f7a7e602007db2b9554df28cd5685839b8
+ python patches 0d98e93189bc278fbc37a50ed7f183bd8aaf249a8e1670a465f0db6bb4f8cf87
@@ version @@
- openssl Version(1.0.2u)
+ openssl Version(1.1.1k)
- python Version(2.7.8)
+ python Version(3.8.11)
Currently this uses diff-like output but we will attempt to improve on this in the future.
One use case for `spack diff` is whenever a user has a disambiguate situation and cannot
remember how two different installs are different. The command can also output `--json` in
the case of a more analysis type use case where we want to save complete data with all
diffs and the intersection. However, the command is really more intended for a command
line use case, and we likely will have an analyzer more suited to saving data
Signed-off-by: vsoch <vsoch@users.noreply.github.com>
Co-authored-by: vsoch <vsoch@users.noreply.github.com>
Co-authored-by: Tamara Dahlgren <35777542+tldahlgren@users.noreply.github.com>
Co-authored-by: Todd Gamblin <tgamblin@llnl.gov>