Relationships between bugs

[Gervase Markham]

developers,

In mozilla.dev.planning, people were lamenting that it's difficult to 
correctly show that one bug was a regression caused by the checkin for 
another. Neither "blocks" nor "depends on" are entirely appropriate.

A (proprietary) bug system I've used in the past has, instead of just 
dependencies, the more general concept of relationships: you give a bug 
number, and then say if it's blocking, blocks, regression, duplicate or 
just related. (We wouldn't use "duplicate", of course.)

shaver rather liked this idea. Is this worth considering? We could also 
use this mechanism to remember that a bug was a clone of another, or 
perhaps that two bugs were for the same underlying problem but on two 
different code branches.

The UI could be simplified to show only those lines where there was 
actually a bug in that relationship:

Depends on: 12345, 34556
Clones:     65433
Branches:   75347 (1.3.1), 84346 (1.2.9)

Add relationship: this bug [ blocks  |V] bug(s): [       ]

where the "blocks" dropdown could be "blocks", "depends on", "is a 
branch version of", "is related to", "was caused by checkin from" etc.

You could still plot dependency graphs using the "blocking" and "blocks" 
relationships as we do now.

What do you guys think?

Gerv