Drupal 8.7.7 expected later this week is the first Drupal release to support extensions compatible with multiple major versions of Drupal. This is huge!

Drupal 9 is planned for June 3, 2020 and we are aiming to make the transition as smooth as possible. In fact we build Drupal 9 in Drupal 8 with API deprecations and optional support for new dependencies (Symfony 4.4 is getting very close, while Drupal 8.7.0 was already Twig 2 compatible). Extensions following these deprecations and making sure they are compatible with the updated dependencies could have codebases that are both compatible with Drupal 8 and 9 at the same time, meaning less support burden and earlier Drupal 9 compatibility. In March 48% of contributed projects on Drupal.org were already "Drupal 9 compatible" (as we could detect at the time), and that increased 54% by July (highfive!). These projects will now have one more thing to do, a one line info.yml file addition, to allow their existing codebase to also run on Drupal 9.

✋Drupal contrib maintainers, thank you! You are already contributing a lot to a successful Drupal 9. Projects that are "compatible with Drupal 9" (as much as we know now) are up to 54% from 48% since March. Deprecated API use is decreasing overall.

You are awesome, keep it up! pic.twitter.com/mHpw4ET0P4

— Gábor Hojtsy (@gaborhojtsy) August 2, 2019

The core: 8.x key did not cut it anymore

Drupal 8 looks at extension .info.yml files and checks for the core: 8.x key to check if the extension can be used with Drupal 8. Unfortunately this was not adequate already due to API additions in Drupal 8 minor releases. You could not specify an extension was only compatible with Drupal 8.4+. People devised clever tricks with dependency on certain versions of the system module, but that was still limiting due to inability to depend on specific patch releases. In case your extension depended on a bugfix being present, you cannot set a dependency on Drupal 8.4.1+ in any way.

Introducing the core_version_requirement key

While solving this issue it became apparent that solving it with the existing core: 8.x key is going to cause backwards compatibility problems with existing Drupal 8 sites. The format of the value could not be changed without causing issues, so a new core_version_requirement key was introduced. This now allows to depend on major and minor versions of core as well as specify multiple version requirements even between multiple minor Drupal versions. For example if you would need a bugfix that is to be included in both Drupal 8.7.23 and 8.8.3 (imaginary future versions) but you wouldn't care for the minor version, then you would use the following, making your module incompatible with versions before the particular bugfix you need on both minor branches, as well as incompatible with all older Drupal 8 branches:

Such precision was never possible before!

The new feature is made available in 8.7.7 to help prepare for Drupal 9, as this makes it possible to also declare Drupal 9 compatibility with the existing codebase you already have. Drupal 8.7.x will get security support up until the planned release of Drupal 9 on June 3, 2020. For extensions that only support Drupal 8.7.7 and later you can now exclusively use the core_version_requirement key. If the extension is also Drupal 9 compatible:

For extensions that also support older versions, you should keep the core: key as well. The core_version_requirement key will be ignored by older Drupal versions, and new versions will validate that you specified non-conflicting requirements in the two keys (with regards to Drupal 8 support) so for extensions supporting older core versions, core_version_requirement also needs to be permissive, but could also allow compatibility with Drupal 9 too:

Read more about this change in the change notice. There is also work ongoing to support dependency metadata from composer.json to drive Drupal's dependency resolution as well. That will coexist with this simpler approach and will provide a more composer-native solution for those who already adopted composer for their extensions. In the meantime at least core_version_requirement will limit what Drupal would install while composer.json requirements will limit what composer will download. Because both Composer and Drupal use the term install, but those don't mean the same thing, here is a comparison chart:

	core: 8.x	system module dependency	core_version_requirement	composer.json dependencies
Can be used from	Drupal 8.0.0+	Drupal 8.0.0+	Drupal 8.7.7+	Drupal 8.0.0+
Allows minor version precision	No	Yes	Yes	Yes
Allows patch version precision	No	No	Yes	Yes
Allows multiple constraints	No	No	Yes	Yes
Limits composer install (download)	No	No	No	Yes
Limits Drupal 8 install	Yes	Yes	Yes	No, unless explicit support is added.
Allows Drupal 8 and 9 install with same codebase	No	No	Yes	No, unless explicit support is added.

What happens to Drupal.org project version numbers then?

So a 8.x-1.3 version of an extension on drupal.org may only be compatible with a subset of core, but that was already the case earlier. Now an 8.x-1.3 version of an extension on drupal.org may also be compatible with Drupal 9. How will this work? Drupal's composer integration already ignores the 8.x prefix from version numbers and only cares about the project specific version. Drupal core already only installs extensions where the core compatibility requirements are met regardless of which version number was the package you used to download (8.x modules may be only compatible with 8.4+ already). So the ultimate plan is to do away with the 8.x prefix in extension numbers entirely on drupal.org and support semantic versions for contributed extensions instead. In the short term, the Drupal.org project browser also needs to be updated to take the dependency metadata and use that to power compatibility filters, instead of merely using the version number prefix.

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I posted my analysis of top uses of deprecated code in Drupal contributed projects in May 2019 two months ago. There are some great news since then. First of all, Matt Glaman of Centarro implemented support for deprecation messages directly in reports, so we can analyse reports much better in terms of actionability. Second, Ryan Aslett at the Drupal Association implemented running all-contrib deprecation testing on drupalci.org (Drupal's official CI environment). While showing that data on projects themselves is in the works, I took the data to crunch some numbers again and the top deprecated API uses are largely the same as two months ago. However, we have full analysis of all deprecation messages and their fixability which gets us two powerful conclusions.

Stop using drupal_set_message() now!

If there is one thing you do for Drupal 9 compatibility, make it getting rid of using drupal_set_message(). As the API documentation for drupal_set_message() explains you should use the messenger service and invoke the addMessage() method on it.

Of the total of 23750 deprecated API use instances found in 7561 projects, 29% of them were instances of drupal_set_message(). So statistically speaking if you stop using this single function, you are already 29% on your way to Drupal 9 compatibility (likely more for most projects).

Dezső Biczó already built automated deprecation fixers covering drupal_set_message() and more, based on rector.

76% of deprecated API use can already be resolved

On top of the 29% of drupal_set_message(), there is another 47% of various other API uses that can be fixed now. This means that those deprecated APIs were marked before Drupal 8.6.0 was released and are therefore in currently unsupported Drupal core versions. So stopping the use of them would still keep your code compatible with all currently supported Drupal core versions. In other words, as of today, drupal.org project maintainers can resolve three quarters of the outstanding code changes for Drupal 9 compatibility. Considering we are still ten months from before Drupal 9's planned release date, this is quite good news!

Upgrade Status is a nice visual tool to explicitly list all the errors in the projects you scan. It provides instructions on how to fix them and immediately fixable issues are highlighted.

Work with project maintainers

You are not a drupal.org project maintainer but want to help? Yay! Based on the above it may be tempting to run to the issue queue and submit issues for fixing all the things. Good plan! One thing to keep in mind though is to work with the maintainers of projects so your help benefits the project most effectively. Drupal.org project owners may specify Drupal 9 plan information that should help you engage with them the best way (use the right meta issue, know of their timeline plans, and so on). Check the project page of projects you are interested to be involved with to make sure you contribute the best way.

More to come

I think the data is super-interesting and I plan to do more with it, for example cross-referencing with project usage. Stay tuned for more information in the future. In the meantime all the source data is available for your mining as well.

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Correction: An earlier version of this post said there were 43% additional fixable deprecations for a total of 72%. Thanks to Ryan Aslett for corrections, the correct numbers are 47% and 76% respectively. Images and text fixed.

Disclaimer: The data is based on the state of contributed projects on July 29, 2019 based on Drupal core's 8.8.x development branch on July 29, 2019. As contributed module maintainers commit fixes, the data will get better. As core introduces more deprecations (until Drupal 8.8.0-alpha1), the data could get worse. There may also be phpstan Drupal integration bugs or missing features, such as not finding uses of deprecated global constants yet. This is a snapshot as the tools and state of code on all sides evolve, the resulting data will be different.

On our way to Drupal 9 every site will need to take care of making updates to their custom code as well as updating their contributed projects. However this time, instead of needing to rewrite code, only smaller changes are needed. Most contributed modules will only need to deal with a couple changes. Collaborating with project maintainers is the best way to get to Drupal 9. The first beta of the Upgrade Status module alongside recent drupal.org changes focus on making this much easier.

Upgrade Status beta provides better insight into Drupal 9 readiness

Take the first beta of the Upgrade Status module and run it on your site. It will provide executive summaries of results about all scanned projects and lets you inspect each individually.

Custom and contributed projects are grouped and summarised separately. You should be able to do all needed changes to your custom code, while for contributed projects you should keep them up to date in your environment and work with the maintainers to get to Drupal 9. The later is facilitated by displaying available update information inline and by pulling the Drupal 9 plan information from drupal.org projects and displaying it directly on the page.

This is how the summary looks like after scanning a few projects:

Digging deeper from the executive summary, you can review each error separately. The beta release now categorizes issues found to actionable (Fix now) and non-actionable (Fix later) categories with a Check manually category for items where it cannot decide based on available information. For custom projects, any deprecation is fixable that has replacements in your environment while for contributed projects supporting all core versions with security support the window is shifted by a year. Only deprecations from two or more releases earlier can be fixed (compared to the latest Drupal release) while keeping Drupal core support. So somewhat ironically, Upgrade Status itself has deprecated API uses that it cannot yet fix (alongside ones it could fix, but we have them for testing purposes specifically):

The module is able to catch some types of PHP fatal errors (unfortunately there are still some in projects that we need to figure out the best way to catch). The @deprecated annotation information guiding you on how to fix the issues found are also displayed thanks to lots of work by Matt Glaman.

Own a Drupal.org project? Direct contributors to help you the way you prefer!

If you own a Drupal.org project that has Drupal 8 code, you should specify your Drupal 9 plans. It is worth spending time to fill in this field to direct contributors to the best way you prefer them help you, so contributions can be a win-win for you and your users alike. Whether it is a META issue you plan to collect work or a specific time in the future you will start looking at Drupal 9 deprecations or a funding need to be able to move forward, letting the world know is important. This allows others to engage with you the way you prefer them to. Additionally to it being displayed in Upgrade Status's summary it is also displayed directly on your project page!

Go edit your project and find the Drupal 9 porting info field to fill in. Some suggestions are provided for typical scenarios:

This will then be displayed on your project page alongside usage and security coverage information. For example, check it out on the Upgrade Status project page.

Thanks

Special thanks for dedicated contributors and testers of the Upgrade Status module who helped us get to beta, especially Karl Fritsche (bio.logis), Nancy Rackleff (ThinkShout), Tsegaselassie Tadesse (Axelerant), Bram Goffings (Nascom), Travis Clark (Worthington Libraries), Mats Blakstad (Globalbility), Tony Wilson (UNC Pembroke), Alex Pott (AcroMedia, Thunder), Charlie ChX Negyesi (Smartsheet), Meike Jung (hexabinær Kommunikation). Thanks to Neil Drumm (Drupal Association) and Angela Byron (Acquia) for collaboration on the Drupal 9 plan field.

Update as of March 16, 2020: an entirely new version of these slides are now available, see http://hojtsy.hu/blog/2020-mar-16/whole-new-version-open-source-state-d…

I created and shared an open source set of editable slides with plenty speaker notes titled "State of Drupal 9" early in May, based on my webinar with Dries and then the Drupal 9 parts of the DrupalCon Seattle Driesnote. I hope that we can bring this know-how to a lot of conferences, meetups and to companies so people are more aware of what is coming, what happens to Drupal 8 and 7, what's so great about Drupal 9 and what are the key tools involved.

Before I even presented the slideshow first, I already got improvement suggestions from people presenting it elsewhere. So the first time I got to present this session in Minsk, Belarus at the kind invitation of DrupalCamp Belarus organizers, it was already improved from when I first published it. I will keep updating the slides and present where I can in the coming months. Please, do it yourself too! Translate, shorten, lengthen, etc. to match your audience and timing needs, as long as the key messages get through. Be an important contributor to Drupal 9 this way!

Here is the recording from DrupalCamp Belarus:

Dwayne McDaniel did some thorough reporting of deprecated code use in all Drupal 8 contributed modules in March. Ultimately this kind of reporting would be best to have on drupal.org but while that is figured out, Dwayne's data set provides a very nice way to mine data about Drupal 9 readiness of contributed modules and to inform our tooling to improve the process. His original numbers showed that almost 44% of contributed modules had no deprecated code use at the time. What I was interested in was how to help the rest of the 56%.

Dwayne created an updated process and a new repository this week with fresh data. I was still curious so I delved right into the data and started mining it. A key question I was interested in is how much of the most widespread deprecations are actionable right now. An actionable deprecation is something core deprecated in a previous version that is not supported anymore, so you can update your code to remove the use of that API. Currently Drupal 8.6 and 8.7 are supported, so deprecations there should only be acted on for your custom code. However deprecations in and before 8.5 are entirely fine to act on.

First I counted the top list of deprecated APIs used from Dwayne's data across all of contributed projects. Then I wrote a script to collate api.drupal.org documentation to the deprecation notices. Ideally phpstan itself would report these messages directly and Matt Glaman is working on that. However since that is still blocked on the phpstan side, one needs a different data source to find the deprecation documentation for each occurrence, so I took to api.drupal.org to get that for now. Once that is found, we can categorize the deprecations into actionable, not actionable and actionable for custom code only. For the later case you know which core version you are using, and that should be an up to date minor version. So you don't need to deal with what core branches the community supports otherwise.

The results look really promising so far in terms of how much contributed modules can make progress on even today. If all already actionable deprecations get resolved, there will be very little left at least of the deprecations we already know.

A month ago Dezső Biczó created a set of proof of concept Rector fixes to automate some of these deprecation fixes, so I opened an issue with this new data set to try and cover the top ones that are not just actionable but approachable to automate.

As with all interesting data sets, this summary is just the tip of the iceberg. There is huge potential to mine this data set for other uses, such as finding modules that potential contributors at an event could contribute fixes to. I don't know yet how much I can continue to work with this data myself, and of course others doing analysis of their own would be more than welcome.

Are you a drupal.org project maintainer? Now would be a good time to fill in your Drupal 9 porting information in your project, so you can let contributors know how to best engage with your in the process towards Drupal 9.

Disclaimer: The data is based on the state of contributed projects on May 20, 2019 based on Drupal core's 8.8.x development branch on May 20, 2019. The lookup on api.drupal.org was not perfect and I found some bugs there that are being resolved as well so the data gets more accurate. Also, as contributed modules will get updated, there will be less uses of deprecated APIs. As core will introduce more deprecations, the data could get worse. There may also be phpstan Drupal integration bugs or missing features, such as not finding uses of deprecated global constants yet. This is a snapshot as the tools and state of code on all sides evolve, the resulting data will be different.

Update as of March 16, 2020: an entirely new version of these slides are now available, see http://hojtsy.hu/blog/2020-mar-16/whole-new-version-open-source-state-d…

I am about to present about Drupal 9 at DrupalCamp Belarus in May and then at Drupal Developer Days Transylvania in June . I already presented an Acquia webinar with Dries Buytaert on the topic, and was on the Lullabot Podcast discussing Drupal 9 with Angie Byron and Nathaniel Catchpole. I am a firm believer that this know-how should spread as far and wide as possible. I should not be needed to travel around the globe to present the topic and people should not spend the same time again to redo slides for their local presentations. There is no intellectual property here to hide, as many people should be aware and excited and participating as possible. The topic should be presented at Drupal Meetups, Camps, and inside your own companies. So the natural next step for me was to create an open source slideshow.

I took all that we learned from the webinar and Dries' keynote at DrupalCon Seattle as well as new technology that emerged since then. I also used a free slide template and Google Slides so you can make a copy for yourself and add your own contact information as well as edit the slides down to shorter or longer timeslots. The 51 slides in my test run for about 35 minutes, leaving 10 minutes for discussion in a 45 minute slot. You would likely need to cut content for shorter sessions. There are only basic buildup animations, so if you need to present offline that is also an option. Edit in your contact/introduction info and export and present as PDF.

The 1.0 version of the slides have been presented by Christian Fritsch at DrupalCamp Munich last week and I updated some content to the current 1.1 version as it is available now. I'll keep updating slides based on all your feedback. I shared the slides with public comments allowed, so keep the feedback coming there, comments here or some other way you can get ahold of me.

Resources to watch/listen to learn more include:

1. Dries' State of Drupal presentation from DrupalCon Seattle
2. Lullabot Podcast on Drupal 9
3. Acquia Webinar on Drupal 9

Thanks to Acquia for funding me to create this slideshow and thank you for presenting it!

Dries Buytaert recently published a great post on how to prepare for Drupal 9. He explains how we build Drupal 9 in Drupal 8 using deprecations and the tools to use to detect use of deprecated code. Acquia funded me and Zoltán Herczog to work on one of the tools in the past few weeks. Zoltán just released the second alpha of Upgrade Status. It is definitely worth a try!

Here is how it works:

Traditionally Drupal was developed in two parallel branches. Take the example of Drupal 7 and 8. There was the supported stable branch of Drupal 7 that received bugfixes only and there was a development branch of Drupal 8 where developers went free to change and improve things the way they have seen best. As the development of Drupal 8 was nearing release, contributed module and theme authors were asked to take a look and release new versions as well in preparation. While the new branch was built with great care, it was not proven yet in various production environments. It also often took quite some time for contributed modules and themes to update.

Drupal 9 is planned to be only 18 months away now, wow! It is already being built in Drupal 8 by marking APIs to be removed in Drupal 9 as deprecated and eventually upgrading some dependency version requirements where needed. Once the Drupal 9 git branch will be open, you will be able to test directly against Drupal 9. That should not stop you from assessing the compatibility of your module with Drupal 9 now. To prepare for compatibility with Drupal 9, you need to keep up with deprecated functionality and watch out for upgraded dependencies (when we know which are those exactly). Of these two, automation can go a long way to help you keep up with deprecated APIs.

(Disclaimer: Dries did not ask/order/suggest/request me to post this neither to make any changes whatsoever.)

I was reading Drupal Confessions with great interest, because my primary job for quite a while now is to help enable the best efforts in the Drupal community to work together to reach new heights. I am really privileged to be able to do this and make a living out of it, it is the job I always dreamed of. I also hope that I am being useful to the Drupal community in doing so. I kept nodding in agreement with the open letter's statements on diversity so I could not get rid of my cognitive dissonance on their connection with reality for several days now. The open letter says "We ask you to fight for us, Dries, to protect us from intolerance, harassment, smearing, bullying, and discrimination, no matter why or where it originates from."

As someone who is getting a paycheck at least indirectly from Dries in the past 10 years, and working as directly with him as possible in Acquia's Office of the CTO for the second half of that period, I have the opportunity to look at his practices in terms of diversity. Which would be the most observable group to learn more from if not his personal department where he directly appoints people?

In the past 5 years I've been closely working with Dries as a remote employee in the Office of the CTO at Acquia, which consisted of 15 people at most at any given time. In this time I worked with at least the following types of people directly in this group (in random order): blind, stutterer, person with ADHD, person with serious sleep problems, person with even more serious sleep problems, divorced, gay, bi, lesbian, asexual, polyamorous, gospel singer, BDSM, religiously raised, atheist, clinically infertile, cosplayer, very tall, short, people from Eastern Europe, Western Europe, US and India, native-borns, immigrants, people in offices, people always working remotely, capitalist, socialist, pacifist, people from a military family, adopting parent, transgender, people with tics, people who don't drink alcohol, etc. The teams I worked on usually had relatively high percentage of women in technical roles. My current team is 50% female, and 1/3rd of the department overall is female. This could not happen by accident.

While none of this represent the whole rainbow of humanity, and it could definitely be further improved, our limited group of 15 people already covered outstanding diversity in my view. Also this is a group that cares, we discuss and live through our struggles and support each other on every step where we can. I would challenge many of those signing the open letter to practice this kind of diversity in their teams. I for one really enjoy the varying values that people brought in and am sad that some of those great people have left to pursue other technical challenges.

In this five years, I never experienced that when hiring people either of these things were considered as a negative or that any person was treated or felt treated badly for any personal life matter. Neither that any of the amazing people who unfortunately left and are covered in the list left because of any of those.

Given that I just cannot get over my cognitive dissonance. Who are being convinced of what?