docs: Document issue and merge request triaging and review guidelines

This documents the practices that I’ve been trying to follow for the
last few years for managing GLib issues and merge requests, and why they
seem to work well enough.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

INSTALL.md

@@ -4,12 +4,12 @@ Simple install procedure
 ```sh
 tar xf glib-*.tar.gz                    # unpack the sources
 cd glib-*                               # change to the toplevel directory
-meson _build                            # configure the build
-ninja -C _build                         # build GLib
+meson setup _build                      # configure the build
+meson compile -C _build                 # build GLib
 
 # Become root if necessary
 
-ninja -C _build install                 # install GLib
+meson install -C _build                 # install GLib
 ```
 
 Requirements

docs/backports.md

@@ -52,6 +52,11 @@ Policy
    - For example, by splitting changes to be backported into a separate commit
      from those which should not be backported, or splitting out changes which
      are more likely to cause conflicts when cherry-picked
+ * Backports should be done as soon as a fix lands on the unstable branch,
+   rather than waiting until when the next stable release is due and then
+   backporting multiple changes from the unstable branch at once. This gives
+   more opportunity for backported changes to be tested, and reduces the chance
+   of backporting the wrong thing, or missing a backport.
  * These rules are not entirely prescriptive: there may be situations where
    maintainers agree that a backport is necessary even if it breaks some of
    these rules, due to the balance of fixing a critical bug vs keeping things

docs/issue-and-merge-request-management.md

@@ -0,0 +1,157 @@
+Issue and merge request management policy
+===
+
+Aims
+---
+
+ * Finding duplicates and related issues and merge requests should be easy when
+   triaging new ones, or when looking back at the history of a particular piece
+   of code
+ * GLib co-maintainers and other interested people should be able to subscribe
+   to notifications for specific parts of GLib without receiving notifications
+   for all activity on GLib
+ * Issues and merge requests which are planned to be in a specific release
+   should not be accidentally left out of that release
+ * GLib co-maintainers should be able to easily see how much work is left to do
+   before a release is ready
+ * Users and developers should have some idea of whether an issue or merge
+   request is being actively worked on, the timescale for its completion, and
+   who’s working on it
+
+Issue triage
+---
+
+ * Issues should be triaged shortly after they are filed. Triage should:
+   - Add labels to categorise the issue, even if it’s about to be closed (this
+     helps with finding related closed issues in future)
+   - Close them immediately if they are a duplicate of an existing issue
+     (`/duplicate #issue`)
+   - Or if they are out of scope, such as a user support question (which should
+     be on https://discourse.gnome.org)
+   - Ask the user for necessary debug information if the issue is valid, a bug,
+     and not enough information has been provided — extracting debug information
+     from users is often time-critical because they can only reproduce an issue
+     under certain conditions, or they lose interest and move on
+   - Assign the issue to an upcoming milestone if it seems urgent
+ * Note that triaging an issue does *not* commit the triager to working on the
+   issue
+ * If an issue is likely to affect a stable release (as well as the unstable
+   `main` branch), assign it to the next micro release milestone for that stable
+   release — the merge request for the fix will be assigned to the next `main`
+   micro release, and its backport to the next stable micro release
+
+Merge request triage
+---
+
+ * Merge requests should be triaged shortly after they are filed. Triage should
+   proceed as for issues, including labels and milestones
+ * The milestone for a merge request is the release it is intended to be
+   included in, and it should match the target branch of the merge request
+   - It’s important to add milestones to merge requests, as they then show up on
+     the milestone page and highlight that the release is not yet ready until
+     they’re all merged
+   - This prevents releases accidentally being made without containing all the
+     fixes they’re supposed to
+ * The ‘assignee’ of the merge request is the person who is working on it,
+   responding to review feedback
+ * The ‘reviewer’ of the merge request is the GLib co-maintainer who is actively
+   reviewing it
+ * Don’t assign someone else as the reviewer or assignee of a merge request
+   unless they have said they are willing to do it, otherwise it gives a false
+   impression that their time is allocated for doing the work
+   - You may assign someone else as a reviewer or assignee when closing or
+     merging a merge request, though, if that helps document who has done the
+     work so they can be appropriately attributed
+
+Labelling issues and merge requests
+---
+
+GLib has a huge number of labels available, one per component of the library
+plus several orthogonal labels. The use of labels allows for:
+ * Easy searching for related issues and duplicates, by filtering on label
+ * Co-maintainers of GLib to subscribe to issue and merge request notifications
+   for a set of labels limited to their interests, meaning they don’t have to
+   subscribe to the full fire hydrant of GLib notifications just to maintain one
+   or two components
+ * High-level prioritization of work, such as prioritizing crashes over new
+   features
+ * Tracking issues and merge requests through the release lifecycle, so that
+   (for example) API additions can be done before the API freeze, and merge
+   requests approved during a code freeze can all be landed when the freeze ends
+
+To subscribe to a specific label, go to
+[the labels page](https://gitlab.gnome.org/GNOME/glib/-/labels) and use the
+subscription selector next to the labels you’re interested in.
+
+Several labels are worth highlighting:
+ * Security: Time-critical security issues, which should typically be marked
+   as confidential.
+ * Merge After Freeze: Merge requests which have been accepted, but which can’t
+   be merged yet as GLib is in
+   [code freeze](https://wiki.gnome.org/ReleasePlanning/Freezes). All MRs tagged
+   like this will be merged en-masse when the freeze ends.
+ * Needs Information: Issues which are blocked due to needing more information
+   from the reporter. These can be closed after 4 weeks if the reporter does not
+   respond.
+ * Not GNOME / Out of Scope: Issues which were closed due to not being within
+   the scope of GLib.
+ * Newcomers: Issues which are suitable for being taken on by newcomers to GLib.
+   When labelling an issue as such, please make sure that the issue title is
+   clear, and the description (or a comment) clearly explains what needs to be
+   done to fix the issue, to give newcomers the best chance of successfully
+   submitting a fix.
+ * Translation / I18N: Issues which relate to translatable strings or other
+   internationalization or localization problems. Adding this label may cause
+   the translation team to be looped into an issue or merge request.
+ * API deprecation: Issues or merge requests which deprecate GLib API, and hence
+   can only land in an unstable release outside an
+   [API freeze](https://wiki.gnome.org/ReleasePlanning/Freezes).
+ * New API: Issues or merge requests which add new GLib API, and hence can only
+   land in an unstable release outside an
+   [API freeze](https://wiki.gnome.org/ReleasePlanning/Freezes).
+ * Intermittent: Issues (such as test failures) which can only be reproduced
+   intermittently.
+ * Test failure: Issues which revolve around a unit test failing. Typically
+   these are opened after a CI run has failed, and are useful for tracking how
+   often a particular failure happens.
+ * Test missing: Merge requests which need a unit test to be written before they
+   can be merged.
+
+Merge request review
+---
+
+ * Assign yourself as the ‘reviewer’ of a merge request when you start review;
+   this helps with tracking notifications, and lets the assignee of the merge
+   request know whether you are providing a comprehensive review or just some
+   drive-by comments
+ * Review the merge request at a high level first: is the change needed, does
+   it make sense, is it structured correctly; then look at the detail of memory
+   management, typos, etc.
+  - If a merge request is large or contains multiple unrelated changes, it is
+    best to ask the author to split it into multiple parallel merge requests.
+    This prevents review comments on one part of the merge request from blocking
+    merging the rest, and allows the reviewer’s time to be split into smaller
+    and more manageable chunks.
+ * Submit all your comments as a single review (rather than adding multiple
+   single comments) to avoid spamming subscribers with multiple notifications.
+ * CC in additional reviewers if their second opinion or domain expertise are
+   needed.
+ * Follow the review through multiple cycles of updates and re-review with an
+   aim to getting the merge request landed — a merge request which gets one
+   round of review and which is then forgotten about is as useful as a merge
+   request which gets no review at all.
+ * While it is useful to highlight related areas of the code needing work that
+   you spot while doing a review, it is not the responsibility of the author of
+   a merge request to fix things outside the scope of their merge request.
+   Reviews which increase the scope of work for a merge request make it much
+   less likely that the merge request will land quickly, which reduces the
+   effective usefulness of the contribution. This wears down contributors and
+   reviewers, as they don’t see closure on what they’ve put time into. It is
+   better to file additional issues for follow-up or related work.
+ * If you cannot follow through a merge request to completion, unassign yourself
+   as the reviewer to make this clear to everybody.
+ * Once a merge request lands, a backport might need to be created for the most
+   recent stable GLib branch (see the [backport policy](./backports.md). It is
+   the responsibility of the maintainers to do this, not the responsibility of
+   the merge request author.
+