Statistics, Google Code-in, Gitlab, Bugzilla

Posted in gnome, lang-en, metrics, user-documentation, wikimedia | 1 Comment

2017: Music.

That annual list of awkward incomplete pop music preferences: Stuff I listened to a lot in the last 12 months. Which did not necessarily get released in 2017. But mostly, I think. And/or enjoyable gigs.

Noga Erez‘ debut album and Zagami Jericho‘s first EP are my favs.
Followed by the latest release by Moby & The Void Pacific Choir, Sevdaliza‘s debut, and Bulp‘s first album.

Looking back at sets, Recondite, Helena Hauff and Setaoc Mass were long nights that left marks.

Looking back at concerts, EMA, Waxahatchee, Lali Puna, Moderat.
Ufomammut and Shobaleader One were banging.
Being able to see Battery live, after all those years.
Someone please send Days’n’Daze on a European tour.

I’d like to thank my bunch.
It’s been a special year, in many ways.

Posted in lang-en, music, non-technical | Comments Off on 2017: Music.

Handling all those mail notifications from the bug tracker

…and following stuff that interests you in an issue tracking system.

I work as a bugmaster in a large project. That means I interact with many people on many topics and try to have a quite hollistic view of what’s going on which requires processing vast amounts of information. Apart from good memory and basic technical understanding (“Wait, this report reminds me of another one which might be related”) I need to follow up and keep track of stuff.

When talking to fellow Wikimedians a common question I receive is: “How do you cope with being subscribed to basically every task in our bug tracker (Wikimedia Phabricator) and receiving those notifications?”

Assuming there is often “How can I cope with all that mail I receive?” hidden between the lines, I’m going to cover that first:

Phabricator options which allow you to follow or collect a list of stuff which interests you:

For completeness: Currently Phabricator does not offer a difference between “I subscribed to this task or got subscribed as I watch the associated project” versus “I got explicitly mentioned in a comment in this task” which can sometimes be unfortunate.

My mail workflow

My workflow is email based. Currently I actually take a look at about 400 to 700 bugmail notifications on a normal workday (I receive way more). Those are the emails that end up as “unread” in a subfolder of my email application (GNOME Evolution).

I apply filters locally, based on projects and/or senders (e.g. bots) of notifications. Phabricator includes a custom “X-Phabricator-Projects” header in every mail notification. As far as i know GMail does not support filtering on custom headers and last time I checked, GMail had a rather “creative” IMAP implementation which did not allow to perform such filtering server-side.
In Bugzilla, managing filter rules was easier as a task has exactly one product and component; further associations are expressed via keywords or whiteboard entries for those who fancy additional UI elements. As Phabricator tasks can have between zero and unlimited projects associated, the order of my local filters (and their criteria) is important.
For some projects and some senders, these filters set the email to “read” status (as in “has been read”) so I might never see these emails.

View of my mail application

My default view is to display only unread messages, to order by message threads, and to display new messages on top.

When going through new (unread) messages I mark most messages as read (keyboard shortcuts are your friend). I keep some messages in “unread” message status whenever I plan to re-check or follow up at some point. I occasionally go through them and nag people.
For urgent tasks which need rechecking rather sooner than later, I mostly end up keeping open tabs in my web browser (if those tasks are not prioritized with the highest (“Unbreak Now!”) priority already anyway).

In addition, I also display some associated projects in the message list for faster orientation which software area the thread is about. I use labels for this, which is a gross hack. (I’d love to have an email application that allows displaying values of arbitrary header lines as a column in the list of emails.)

Obviously, such an email based workflow makes it hard to pass work to someone else for a limited time (the so-called “vacation” concept). Some mail services allow proxying though.

Expectations and service level

And the social part: As Wikimedia Phabricator is used by more and more teams (not only by engineering but also by chapters, to plan sessions at conferences, etc.), I clarified which service level to expect from me. So the page that describes my job says: As the bugwrangler cannot support every single project and task in Phabricator to the same extent, maintainers and teams are more than welcome to contact the bugwrangler to express support requests for managing their tasks.

Do you have better workflows or tips to share?

Posted in bugzilla, lang-en, phabricator | Comments Off on Handling all those mail notifications from the bug tracker

Wikimedia in Google Code-in 2016

(Google Code-in and the Google Code-in logo are trademarks of Google Inc.)

Google Code-in 2016 has come to an end. Wikimedia was one of the 17 organizations who took part to offer mentors and tasks to 14-17 year old students exploring free and open source software projects via small tasks.

Congratulations to our 192 students and 46 mentors for fixing 424 tasks together!

Being one of the organization admins, deciding on your top five students at the end of the contest always takes time and discussions as many students have provided impressive work and it hurts to have to put a great contributor on the 6th or 7th place.
Google will announce the Grand Prize winners and finalists on January 30th.

Reading the final feedback of students always re-assures that all the effort mentors and organization admins put into GCI are worth it:

  • In 1.5 month, I learned more than in 1.5 year. — Filip
  • I know these things will be there forever and it’s a big thing for me to have my name on such a project as MediaWiki. — Victor
  • What makes kids like me continue a work is appreciation and what the community did is give them a lot. — Subin
  • I spent my best time of my life during the contest — David

Read blogposts by GCI students about their experience with Wikimedia.

To list some of the students’ achievements:

  • Many improvements to Pywikibot, Kiwix (for Wikipedia offline reading), Huggle, WikiEduDashboard, Wikidata, documentation, …
  • MediaWiki’s Newsletter extension received a huge amount of code changes
  • The Pageview API offers monthly request stats per article title
  • jQuery.suggestions offer reason suggestions to block, delete, protect forms
  • A {{PAGELANGUAGE}} magic word was added
  • Changes to number of observations in the Edit Quality Prediction model
  • A dozen MediaWiki extension pages received screenshots
  • Lots of removal of deprecated code in MediaWiki core and extensions
  • Long CREDIT showcase videos got split into ‘one video per topic’ videos on Wikimedia Commons
  • Proposals for a redesign of the Romanian Wikipedia’s main page
  • Performance improvements to the importDump.php maintenance script
  • Converted Special:RecentChanges to use the OOUI library
  • Allow users to apply change tags as they make logged actions using the MediaWiki web API
  • Added some hooks to Special:Unblock
  • Added a $wgHTTPImportTimeout setting for Special:Import
  • Added ability to configure the web service endpoint and added phpcs checks in MediaWiki’s extension for Ideographic Description Sequences
  • Glossary wiki pages follow the formatting guidelines
  • Research on team communication tools

We also received valuable feedback from our mentors on what we can improve for the next round.

Thanks to everybody for your friendliness, patience, and help provided.
Thanks for your contributions to free software and free knowledge.
See you around on IRC, mailing lists, tasks, and patch comments!

Posted in lang-en, wikimedia | Tagged | Comments Off on Wikimedia in Google Code-in 2016

2016: Music.

That annual list of awkward incomplete pop music preferences: Stuff I listened to a lot in the last 12 months (and which did not necessarily get released in 2016).

When it comes to concerts:
  • Supersilent left me without words.
  • In Electronica, Digitalism were beautifully vibrant and energetic (cannot say if it was a DJ set or a concert – somewhere in between).
    Also enjoyed numerous challenging Neoru DJ sets (one flyer really called that “post-genre”), Poliça, Zola Jesus, and Bulp.
  • In the guitar section, blessed to see Ignite again after all those years (still the band I’ve seen the most) and (classic) Motorpsycho.
  • In Hiphop, it was a pleasure to see and talk to Little Simz and Angel Haze (see last year). Die Antwoord were entertaining as expected.
When it comes to headphones:

Thanks to my peeps. You know who you are. :)

Posted in lang-en, music, non-technical | Comments Off on 2016: Music.

2016 snapshots.






Posted in lang-en, misc, non-technical, prague | Comments Off on 2016 snapshots.

Code review in open source projects: Influential factors and actions

Coming from “Prioritizing volunteer contributions in free software development”, the Wikimedia Foundation allowed me to spend time on research about code review (CR) earlier in 2016. The theses and bullet points below incorporate random literature and comments from numerous people.
While the results might also be interesting for other free and open source software projects, they might not apply to your project for various reasons.

In Wikimedia we would like to review and merge better code faster. Especially patches submitted by volunteers. Code Review should be a tool and not an obstacle.
Benefits of Code Review are knowledge transfer, increased team awareness, and finding alternative solutions. Good debates help to get to a higher standard of coding and drives quality.[A1]

I see three dimensions of potential influential factors and potential actions (that often cannot be cleanly separated):

  • 3 aspects: social, technical, organizational.
  • 2 roles: contributor, reviewer.
  • 3 factors: Patch-Acceptance/Positivity-Likeliness, Patch-Time-to-review/merge, Contributor onboarding (not covered here).

In general, “among the factors we studied, non-technical (organizational and personal) ones are betters predictors” (means: possible factors that might affect the outcome and interval of the code review process) “compared to traditional metrics such as patch size or component, and bug priority.”[S1]

Note that Wikimedia plans to migrate its code review infrastructure from Gerrit to Phabricator Differential at some point.

Unstructured review approach

An unstructured review approach potentially demotivates first patch contributors, but fast and structured feedback is crucial for keeping them engaged.

Set up and document a multi-phase, structured patch review process for reviewers: Three steps proposed by Sarah Sharp for maintainers / reviewers[A2], quoting:

  • Fast feedback whether it is wanted: Is the idea behind the contribution sound? / Do we want this? Yes, no. If the contribution isn’t useful or it’s a bad idea, it isn’t worth reviewing further. Or “Thanks for this contribution! I like the concept of this patch, but I don’t have time to thoroughly review it right now. Ping me if I haven’t reviewed it in a week.” The absolute worst thing you can do during phase one is be completely silent.[A2]
  • Architecture: Is the contribution architected correctly? Squash the nit-picky, perfectionist part of yourself that wants to comment on every single grammar mistake or code style issue. Instead, only include a sentence or two with a pointer to coding style documentation, or any tools they will need to run their contribution through.[A2]
  • Polishing: Is the contribution polished? Get to comment on the meta (non-code) parts of the contribution. Correct any spelling or grammar mistakes, suggest clearer wording for comments, and ask for any updated documentation for the code[A2]

Lack of enough skillful, available, confident reviewers and mergers

Not enough skillful or available reviewers and potential lack of confident reviewers[W1]? Not enough reviewers with rights to actually merge into the codebase?

  • Capacity building: Discuss consider handing out code review rights to more (trusted) volunteers by recognizing active users who mark patches as good-to-go or needs-improvement (based on statistics)? Encourage them to become habitual and trusted reviewers; actively nominate to become maintainers[W2]? Potentially recognize people not executing their code review rights anymore. Again this requires statistics (to identify very active reviewers) and stakeholders (to decide on nominations).
  • Review current code review patch approval handout practice (see Wikimedia’s related documentation about +2 rights in Gerrit).
  • Consider establishing prestigious roles for people, like “Reviewers”?[W3]
  • “we recommend including inexperienced reviewers so that they can gain the knowledge and experiences required to provide useful comments to change authors”[S2]; Reviewers who have prior experience give more useful comments as they have more knowledge about design constraints and implementation.[S2]

Under-resourced or unclear responsibilities

Lack of repository owners / maintainers, or under-resourced or unclear responsibilities when everyone expects someone else to review. (For the MediaWiki core code repository specifically, see related tasks T115852 and T1287.)

“Changes failing to capture a reviewer’s interest remain unreviewed”[S3] due to self-selecting process of reviewers, or everybody expects another person in the team to review. “When everyone is responsible for something, nobody is responsible”[W4].

  • Have better statistics (on proposed patches waiting for review for a long time) to identify unmaintained areas within a codebase or codebases with unclear maintenance responsibilities.
  • Define a role to “Assign reviews that nobody selects.”[S3] (There might be (old) code areas that only one or zero developers understand.) Might need an overall “Code Review wrangler” position similar to a Bugwrangler/Bugmaster.
  • Clarify and centrally document which Engineering/Development/Product teams are responsible for which codebases, and Team/Maintainer ⟷ Codebase/Repository relations (Example: “How Wikimedia Foundation’s Reading team manages extensions”)
  • Actively outreach to volunteers for unmaintained codebases via Requesting repository ownership? Might need an overall “Code Review wrangler” position similar to a Bugwrangler/Bugmaster.
  • Advertise a monthly “Project in need of a maintainer” campaign on a technical mailing list and/or blog posts?

Hard to identify good reviewer candidates

Hard for new contributors to identify and add good reviewers.

“choice of reviewers plays an important role on reviewing time. More active reviewers provide faster responses” but “no correlation between the amount of reviewed patches on the reviewer positivity”.[S1]

  • Check “owners” tool in Phabricator “for assigning reviewers based on file ownership”[W5] so reviewers get notified of patches in their areas of interest. In Gerrit this exists but is limited.
  • Encourage people to become project members/watchers.[W6]
  • Organization specific: Either have automated updating of outdated manual list of Developers/Maintainers, or replace individual names on the list of Developers/Maintainers by links to Phabricator project description pages.
  • In the vague technical future, automatic reviewer suggestion systems could help[S2], like automatically listing people who lately touched code in a code repository or related tasks in an issue tracking system and the length of their current review queue. (Proofs of concept have been published in scientific papers but code is not always made available.)

Unhelpful reviewer comments

Due to unhelpful reviewer comments, contributors spend time on creating many revisions/iterations before successful merge.

  • Make sure documentation for reviewers states:
    • Reviewers’ CR comments considered useful by contributors: identifying functional issues; identifying corner cases potentially not covered; suggestions for APIs/designs/code conventions to follow.[S2]
    • Reviewers’ CR comments considered somewhat useful by contributors: coding guidelines; identifying alternative implementations or refactoring[S2]
    • Reviewers’ CR comments considered not useful by contributors: Authors consider reviewers praising on code segments, reviewers asking questions to understand the implementation, and reviewers pointing out future issues not related to the specific code (should be filed as tasks) as not useful.[S2]
    • Avoid negativity and ask the right questions the right way. As a reviewer, ask questions instead of making demands to foster a technical discussion: “What do you think about…?” “Did you consider…?” “Can you clarify…?” “Why didn’t you just…” provides a judgement, putting people on the defensive. Be positive.[A1]
    • If you learned something or found something particular well, give compliments. (As code review is often about critical feedback only.)[A1]
    • Tool specific: Agree and document how to use Gerrit’s negative review (CR-1): “Some people tend to use it in an ‘I don’t like this but go ahead and merge if you disagree’ sense which usually does not come across well. OTOH just leaving a comment makes it very hard to keep track – I have been asked in the past to -1 if I don’t like something but don’t consider it a big deal, because that way it shows up in Gerrit as something that needs more work.”[W7]
    • Stakeholders with different expertise areas to review aspects need to split reviewing parts of a larger patch.

Weak review culture

Prioritization / weak review culture: more pressure to write new code than to review patches contributed? Code review “application is inconsistent and enforcement uneven.”[W8]

  • Introduce and foster routine and habit across developers to spend a certain amount of time each day for reviewing patches (or part of standup), and team peer review on complex patches[A1].
  • Write code to display “a prominent indicator of whether or not you’ve pushed more changesets than you’ve reviewed”[W9]?
  • Technical: Allow finding / explicitly marking first contributions by listing recent first contributions and their time to review on korma’s code_contrib_new_gone in T63563. Someone responsible to ping, follow up, and (with organizational knowledge) to add potential reviewers to such first patches. Might need an overall “Code Review wrangler” position similar to a Bugwrangler/Bugmaster.
  • Organization specific: Contact the WMF Team Practices Group about their thoughts how this can be fostered?

Workload of existing reviewers

Workload of existing reviewers; too many items on their list already.

Reviewer’s Queue Length: “the shorter the queue, the more likely the reviewer is to do a thorough review and respond quickly” and the longer the more likely it takes longer but “better chance of getting in” (due to more sloppy review?)[S1].

  • Code review tool support to propose reviewers or display on how many unreviewed patches a reviewer is already added so the author can choose other reviewers. Proposal to add reviewers to patches[W2] but this requires already good knowledge of the community members as otherwise it just creates more noise.
  • Potentially document that “two reviewers find an optimal number of defects – the cost of adding more reviewers isn’t justified […]”[S3]
    • Documentation for reviewers: “we should encourage people to remove themselves from reviewers when they are certain they won’t review the patch. A lot of noise and wasted time is created by the fact that people are unable to keep their dashboards clean”[WA]
  • Tool specific: Gerrit’s negative review (CR-1) gets lost when a reviewer removes themselves (bug report) hence Gerrit lists (more) items which look unreviewed. Check if same problem exists in Phabricator Differential?
  • Tool specific: Agree whether ‘Patch cannot be merged due to conflicts; needs rebasing’ should be a reason to give CR-1[WB] in order to get a ‘cleaner’ list? (But depending on the Continuous Integration infrastructure tools of your project, such rejection via static analysis might happen automatically anyway.)

Poor quality of contributors’ patches

Due to poor quality of contributors’ patches, reviewers spend time on reviewing many revisions/iterations before successful merge. Might make reviewers ignore instead of reviewing again and again giving yet another negative CR-1 review.

  • Make sure documentation for contributors states:
    • Small, independent, complete patches are more likely to be accepted.[S4]
    • “[I]f there are more files to review [in your patch], then a thorough review takes more time and effort”[S2] and “review effectiveness decreases with the number of files in the change set.”[S2]
    • Small patches (a maximum of 4 lines changed) “have a higher chance to be accepted than average, while large patches are less likely to be accepted” (probability) but “one cannot determine that the patch size has a significant influence on the time until a patch is accepted” (time)[S5]
    • Patch Size: “Review time [is] weakly correlated to the patch size” but “Smaller patches undergo fewer rounds of revisions”[S1]
    • Reasons for rejecting a patch (not all are equally decisive; “less decisive reasons are usually easier to judge” when it comes to costs explaining rejections):[S6]
      • Problematic implementation or solution: Compilation errors; Test failures; Incomplete fix; Introducing new bugs; Wrong direction; Suboptimal solution works but there is a more simple or efficient way); Solution too aggressive for end users; Performance; Security
      • Difficult to read or maintain: Including unnecessary changes (to split into separate patch); Violating coding style guidelines; Bad naming (e.g. variable names); Patch size too large (but rarely matters as it’s ambiguous – if necessary it’s not a problem); Missing docs; Inconsistent or misleading docs; No accompanied test cases (When should “No accompanied test cases” be a reason for a negative review? In which cases do we require unit tests?[W4] This should be more deterministic); Integration conflicts with existing code; Duplication; Misuse of API; risky changes to internal APIs; not well isolated
      • Deviating from the project focus or scope: Idea behind is not of core interest; irrelevant or obsolete
      • Affecting the development schedule / timing: Freeze; low urgency; Too late
      • Lack of communication or trust: Unresponsive patch authors; no discussion prior to patch submission; patch authors’ expertise and reputation[S6]
      • cf. Reasons of the Phabricator developers why patches can get rejected
    • There is a mismatch of judgement: Patch reviewers consistently consider test failures, incomplete fix, introducing new bugs, suboptimal solution, inconsistent docs way more decisive for rejecting than authors.[S6]
    • Propose guidelines for writing acceptable patches:[S6]
      • Authors should make sure that patch is in scope and relevant before writing patch
      • Authors should be careful to not introduce new bugs instead of only focussing on the target
      • Authors should not only care if the patch works well but also whether it’s an optimal solution
      • Authors should not include unnecessary changes and should check that corner cases are covered
      • Authors should update or create related documentation[S6] (for Wikimedia, see Development policy)
    • Patch author experience is relevant: Be patient and grow. “more experienced patch writers receive faster responses” plus more positive ones. In WebKit, contributors’ very first patch is likely to get positive feedback while for their 3rd to 6th patch it is harder.[S1]
  • Agree on who is responsible for testing and document responsibility. (Tool specific: Phabricator Differential can force patch authors to fill out a test plan.)[W7]

Likeliness of patch acceptance depends on: Developer experience, patch maturity; Review time impacted by submission time, number of code areas affected, number of suggested reviewers, developer experience.[S7]

Hard to realize a repository is unmaintained

Hard to realize how (in)active a repository is for a potential contributor.

  • Implement displaying “recent activity” information somewhere in the code repository browser and code review tool, to communicate expectations.
  • Have documentation that describe steps how to ask for help and/or take over maintainership, to allow contributors to act if interested in the code repository. For Wikimedia these docs are located at Requesting repository ownership.

No culture to improve changesets by other contributors

Changesets are rarely picked up by other developers[WB]. After merging, “it is very difficult to revert it or to get original developers to help fix some broken aspect of a merged change”[WB] regarding followup fixing culture.

  • Document best practices to amend a change written by another contributor if you are interested in bringing the patch forward.

Hard to find related patches

Hard to find existing “related” patches in a certain code area when working on your own patch in that area, or when reviewing several patches in the same code area. (Hence there might also be some potential rebase/merge conflicts[WB] to avoid if possible.)

  • Phabricator Differential offers “Recent Similar Open Revisions”.[WC] Gerrit might have such a feature in a newer version.[WD]

Lack of synchronization between teams

Lack of synchronization between developer teams: team A stuck because team B doesn’t review their patches?

  • Organization specific: Wikimedia has regular “Scrum of Scrum” meetings of all scrum masters across teams, to communicate when the work of a team is blocked by another team.

Comment which important factors that you have experienced are missing!


Posted in computer, lang-en, metrics, phabricator, wikimedia | 2 Comments

Restricting cookies vs. using Google Hangouts

No idea if this is useful to anyone but it was an interesting exercise.

By default I have disabled storing cookies in my main web browser. I have a custom list of specific web sites that I allow to set cookies. (Whether that makes any sense regarding all the other data your browser sends which might create a unique fingerprint anyway is a different question up to your personal judgement/opinion on “privacy” and not the topic here.)

Ideally that whitelist would only include web sites that use my data in a way that I can agree with. In reality, services exist that could either be considered convenient (like Facebook; if you want to use their services you could use a private browser session every time and reenter your password, or use a separate browser to isolate Facebook’s cross-site cookie pollution) or services that your employer or customers use or expect for whatever reasons.

Google Hangouts video calls and Google Hangout text chats (which are proprietary after dropping XMPP) are used by some of my co-workers.
I have been wondering for a while which specific Google sites to allow setting cookies in order to be able to use these services but could not find information on the web. Google lists a bunch of domains but that list seems neither specific nor complete.
Going for trial and error, I removed any Google cookies (which might require more than a simple string search due to sites such as, removed any potential rules allowing Google cookies, set my browser to not allow any cookies, and see how far I can make it working around random error messages and getting logged out immediately after having logged in.

I ended up allowing the sites,, clients[1-6],, people-pa.clients[1-6],, to set cookies. Some of these were trickier to find but your web browser’s developer tools allow you to check which sites want to set cookies.

And now back to actual work.

Posted in computer, lang-en | 4 Comments

Rewriting code review documentation, on paper.

At Wikimedia, for the last months I’ve been on and off rewriting our on-wiki technical Gerrit/Git/Code Review documentation.

Code review related documentation

That included improving the onboarding steps like setting up Git and Gerrit (related task; 135 edits), the contribution guidelines and expectations for patch authors (related task; 28 edits), and to some extent the guidelines for patch reviewers (related task; 23 edits).

Among the potential next steps there is agreeing on a more structured, standardized approach for reviewing code contributions. That will require engineering and development to lead efforts to have teams follow those guidelines, to establish a routine of going through unreviewed patches, and other potential iterative improvements.

Printed documentation.

On paper

I’m not a person carrying around a laptop and don’t use mobile phones much. The more text/comments to tackle (or seperate pages covering related topics), the more I prefer working on paper. (That’s also how I started high-level planning the GNOME Evolution user docs rewrite.)
It might be archaic but paper allows me to get an overview of several pages/documents at the same time. (I could probably also buy more or bigger screens?) I can mark and connect sections that are related and should not be in four different places (like Troubleshooting related information or operating system specific instructions). Plus trying to be accountable and transparent I end up performing lots of small atomic changes with a proper change summary message so I can cross out sections on paper that are done on the wiki.
Paper especially works for me when thinking about topics that still require finding an approach. So I end up in the park or in a pub.

In a future blog post I’m going to cover what I’ve learned about aspects and issues of code review.

Posted in computer, lang-en, user-documentation, wikimedia | Comments Off on Rewriting code review documentation, on paper.

GUADEC 2016.

Filthy attempts on the unconference session scheduling whiteboard by so-called “friends” trying to trick me into literally ‘something’.
They won’t succeed.

#makeandrenevertalkagain #noicecreamleftbehind

Posted in computer, gnome, lang-en | Comments Off on GUADEC 2016.