When the decision was made at DrupalCon Prague to remove the major version (D6/7 => D8) upgrade path in lieu of using Migrate for major version upgrades, we agreed that we were not going to hold up Drupal 8's release on Migrate being supported.

We need to clarify what this means for how and when Migrate will be supported in 8.0.0's release and beyond.

Proposed resolution

Release notes blurb

Drupal 8.0.0 ships with a migration path from Drupal 6 to Drupal 8, and from Drupal 7 to 8 (in progress), as well as automated test coverage to keep the code maintainable. The migration path is accessible from the contributed Migrate Upgrade module, via both Drush and a UI.

Migrate in core is considered experimental until at least 8.1.0, and "Migrate critical" issues it exposes will not block the release of 8.0.0.

Migrate in core will be considered release-ready and remove its “Experimental” label in the earliest 8.x minor release possible (e.g. 8.1.0, 8.2.0), once it has:

  1. A complete 6 -> 8 migration path (prioritized first due to D6’s impending end of life)
  2. A UI in core that passes usability/accessibility gates
  3. No remaining “Migrate critical” issues.

Ideally, also a complete 7 -> 8 migration path, but that can individually be marked as “Experimental” if it is not ready in time.

Core process notes:

  • The UI can be added to core anytime up to RC1, or in a later minor release release (e.g. 8.1.0, 8.2.0).
  • Any critical issues uncovered in the migration path should be filed as "major" priority, with the "Migrate critical" tag.
  • If a core patch you're working on fails a Migrate test, reach out to a Migrate maintainer for help. (For critical issues, in very rare circumstances, and only at core committer discretion, this policy might apply.)

Remaining tasks

Final(?) review. Document in handbook.

Note that the beginning of this discussion contains frustrated comments about the aforementioned policy issue. Around comment #17 the discussion shifts to the overall Migrate policy.

The current proposal comes from #34.


chx’s picture

Issue summary: View changes
chx’s picture

Title: Roll back migrate from core » [policy, no patch] Establish a sane migrate policy
Priority: Major » Critical
Issue summary: View changes
chx’s picture

Issue summary: View changes
benjy’s picture

It's hard to believe we'd consider just commenting out Migrate tests. It feels very much like we've given up on the possibility of Migrate making 8.0.0 which is disappointing when the D6 to D8 migration path is complete give or take a few bugs.

I'd be interested to see some examples of "extraordinary cases" where we can fix critical's and break Migrate's tests in a way that isn't reasonably easy to fix.

chx’s picture

New policy recommendation:

The announcement about the new migrate policy was sent out without talking to any migrate maintainers first due to some miscommunication. Sorry about that. The policy did not intend to sideline migrate but to streamline fixing criticals. If you need to comment out migrate tests to get a critical passing, that is fine but whether the issue gets committed with commented out tests should be only in exceptional circumstances and is down to discretion. The migrate folks (at least benjy and chx are always easy to find) are always ready to help with migrate problems.

chx’s picture

Issue summary: View changes
xjm’s picture

I don't see how #5 is in any way different from what the g.d.o/core post already says, except that chx seems to be saying that we owe him an apology for not consulting him even though he's stepped down.

Is Moshe not considered a member of the Migrate initiative?

Every patch that gets reviewed and committed to core goes through the four core maintainers, who will decide what to accept in a patch, so I don't see what this would help other than trying to stir up drama.

xjm’s picture

Re: #4, see #2297213: [meta] Ensure that there are no critical Migrate issues before releasing the migration path. These issues would still be considered Migrate criticals. Having to reach out to the Migrate team and get them to fix your tests isn't a reliable process. Filing a migrate-critical issue is and ensures that the issues will be looked at before release. We are certainly not considering "just commenting out" the tests for no good reason, which I think has been clearly stated in the post and in private emails since. I hope?

@larowlan was stuck on Migrate for #2228763: Create a comment-type config entity and use that as comment bundles, require selection in field settings form for days; he spent days where his full attention was devoted to getting the migrate tests working. A more efficient situation would be to do what we're proposing here: @larowlan continuing work on his patch, and then someone with Migrate expertise addressing the Migrate critical separately. In most cases I'd expect these patches to land within a week of each other, if the Migrate team is as available to work on them as suggested.

chx’s picture

Sigh. I spent a bit more than an hour discussing this with catch. The problem is

The current workflow is "i should learn migrate perhaps" if you get a migrate test fail and we will be there to help but it means the team (which is quite thin these days) doesn't need to solve itself everything


This policy means "oh a migrate test fail, irrelevant, let's kick it down to a major and let's hope someone else solves it"

catch said:

I would be happy to throw away 'easily' and have a process.

easily in "When we do have a patch which is Critical but cannot easily be adjusted to pass Migrate's unit tests,"

and that's the replacement I came up with.

Regarding the comment issue

The migrate bug found a bug in CommentType. this was the interdiff that got it passed. careful what you are asking for. migrate is like a second set of testing

It would've been more efficient to get to green and then work out the migrate fail in parallel which is what my new policy suggests but it is not a separate issue because the migrate bug was a comment type bug! The policy would make the migrate team figure out all the newest (undocumented) bugs. That's not tenable.

Also the message matters, quite a lot that's why I added "The policy did not intend to sideline migrate but to streamline fixing criticals" which is everything but clear from the current policy.

Finally, who cares whether you talk to me but noone talked to benjy also the way we are supposed to work is to file an issue and then an announcement on gdo/core that a discussion is talking place. webchick in #1236280-49: We need a central place for core contributors broadcast their business when this place was created

It really feels like this new list needs to be more like an "announcement only" list that points people to important discussions happening wherever the most appropriate place is to find more information/participate in the discussion, probably favouring "meta" issues because we at least know from Drupal versions 1 through 7 that developers can use issue queues.

I can't remember building that place for handing-down-stone-tablets-from-the-Mount-Sinai.

xjm’s picture

Thanks @chx for taking the time to write that out. It helps me to understand your concerns a lot better.

So I think maybe you and catch think that posting a policy issue and then linking that meta issue from g.d.o/core would have been better, rather than just putting the information on g.d.o/core? That way benjy could have had a chance to get questions about it clarified (rather than there being a misunderstanding about it that makes it seem like Migrate is not considered important). I'd have been fine with this being posted as a policy issue with a link from g.d.o/core, rather than just on g.d.o/core, if that makes folks more comfortable.

My only concern is that this originated as an email discussion between core maintainers, and to some extent I think that part of the purpose of having core maintainers is to make efficient decisions about fiddly details of core process rather than having to have six-month-long bikesheds to achieve consensus about how to tell core maintainers how to do their jobs. It's important to get the full community's input for big things, but really all this policy does is clarify how we handle test failures for tests maintained in core that should not block 8.0.0, issue-management-wise. (Edit: keeping in mind that the actual decision that Migrate should not block 8.0.0 was a condition of adding it in the first place.)

xjm’s picture

Also, I don't particularly want to be pedantic, but... this is a Migrate-critical.

chx’s picture

Surely there are issues that need to be decided unilaterally by the project leadership. For example, "above 15+15 critical issues we do not commit features". Putting this up for community would result in either a Monthy Python sketch ("let's use the number of broken plates this week as a gate instead" or some equally useful and easy to determine mark) or a proper godwin'd flame war ("no it must be 16 you godless heathen!") or both. Certainly entertaining but not quite useful.

On the other hand, putting this up for community discussion could hardly result in a six month bikeshed. We always had the agreement that migrate will not necessarily be added to D8.0.0 now evolved into not exposing / supporting it for D8.0.0. Within that framework, there's not a lot of disagreement possible. And mind you, I do not disagree with the thrust of this policy. What I disagree with is the message it sends and the precedent it sets as I elaborated above. If the announcement would've gone as a pointer to an issue then we could've quickly hashed the wording out there and then put it up in a handbook page to everyone's satisfaction. With noone's feelings hurt.

chx’s picture

We also need to add what is the official state of migrate in Drupal 8.0.0 because I just received this message from one of the contributors "aside of personal issues, I stopped pushing on multilingual migrate because I thought it would be postponed". My understanding is we will add the UI when ready and rip it out if it's holding up the release?

benjy’s picture

Somehow un-followed this issue after my comment so only just seen these responses now.

@larowlan was stuck on Migrate for #2228763: Create a comment-type config entity and use that as comment bundles, require selection in field settings form for days; he spent days where his full attention was devoted to getting the migrate tests working.

Maybe someone should have asked chx or I? larowlan asked me a question on IRC regarding this issue, it wasn't made clear that it had been holding an important issue up for days.

Is Moshe not considered a member of the Migrate initiative?

Sure, but from what i'm aware, he never discussed it with anyone else on the migrate team

Since we raised our initial concerns with the policy, I've been pinged every time a migrate test has been commented out by a core maintainer and that gives me the opportunity to assist with issues right away. When i've been pinged, i've solved all migrate related problems before the original issue has even been committed.

chx’s picture

So a month has passed and as I predicted migrate has almost completely died. Here's a quote from IRC:

chx: aside of personal issues, I stopped pushing on multilingual migrate because I thought it would be postponed

So it's time to decide: do you want to kill migrate in core dead or do you want to apologize and re-energize this effort? Decide.

xjm’s picture

I'm sorry but, what is the outstanding concern? We've already addressed the original misunderstanding, and it sounds like things are working out per:

Since we raised our initial concerns with the policy, I've been pinged every time a migrate test has been commented out by a core maintainer and that gives me the opportunity to assist with issues right away. When i've been pinged, i've solved all migrate related problems before the original issue has even been committed.

@benjy, do you have any other concerns here?

chx’s picture

Issue summary: View changes

So we should send out a migrate release policy / status upgrade to gdo/core, I think. Something like:

Drupal 8.0.0 will contain a migration path from Drupal 6 to Drupal 8. When the UI is ready and (most) known bugs are fixed then it'll be possible to run the migration from the UI. Adding the UI can happen up to RC1 or a minor release release. If the UI is not ready or we not comfortable with supporting the migration path then drush can be used to run the migration.

Right now, there are a few known issues, relatively small with the single language migration. Multilingual migration is being worked on. There is a possibility that Views migration will happen as well.

Once the Drupal 6 to Drupal 8 migration is stable, we will work on adding Drupal 7 to Drupal 8.

xjm’s picture

Title: [policy, no patch] Establish a sane migrate policy » [policy, no patch] Clarify policy on the inclusion of Migrate in Core for 8.0.0

Discussed with @benjy, @chx, and @ultimike this evening. @chx pointed out that we do not have in writing anywhere the original decision about how and when Migrate would be included in core, and suggested that we should clarify that, for anyone who had the impression that the Migrate test policy post about criticals meant Migrate wasn't still a core priority. Something like:

  • Migrate in core does not block the release of 8.0.0 and is not yet officially supported. See #2297213: [meta] Ensure that there are no critical Migrate issues before releasing the migration path.
  • We maintain Migrate's tests in core despite that it is not yet officially supported, in order make the code maintainable. The test policy announced earlier is only for critical issues in very rare circumstances, and only at core maintainer discretion. The best course of action is to reach out to a Migrate maintainer first for help with Migrate test issues.
  • Migrate in core will be considered supported (and release-ready) when it is complete, including a UI with sound UX.
  • Migrate in core, and the specific migration paths (D6->D8 and D7->D8, etc.) can become supported and included for 8.0.0 any time up until RC1, once they are complete and releasable (no Migrate criticals, per #2297213: [meta] Ensure that there are no critical Migrate issues before releasing the migration path).
  • If Migrate (or a specific migration path) is not ready in time for 8.0.0-rc1, it will be removed and made a top priority for the next minor version, 6 months later (i.e. 8.1.0). The D6->D8 migration path is the first priority, and the D7->D8 migration path is the next priority.

Does that sound right?

benjy’s picture

Thanks xjm, all that sounds pretty good to me. Just one thing, surely there would be a benefit of leaving migrate in core for release even if the migrations can only be run from Drush? It would be a shame to remove a working D6->D8 migration path because we didn't have the UI?

xjm’s picture

Yeah, chx mentioned that in IRC as well. I can see how it might work to include the Migration path with no UI, but available to Drush, if there were no Migrate-critical issues with it otherwise.

webchick’s picture

So this was not clear to me, but #18 was apparently a summary of a discussion that happened, not necessarily a decree by core committers. Given there's not yet a decree here, this policy is something we need to figure this out before release, so tagging.

catch’s picture

#18 with the modification in #19/#20 still works for me.

Boils down to:


1. Announce it's supported
2. Include an enabled UI.
3. Bugs in migrations are critical

not supported:

1. Don't announce it's supported
2. Don't include an enabled UI.
3. Bugs in migrations not critical

6/7 and eventually 8-8 migrations can all live in core without being supported, and it'd be possible to run them from drush in that state, just at-own-risk.

webchick’s picture

OK, so basically bullet points #1-4 but not #5 in #18 and #19/20?

catch’s picture

Yeah just like that.

webchick’s picture

Issue tags: +Migrate critical


webchick’s picture

Also, this issue is already explicitly captured in #2485119: [meta] The Drupal 8.0.0-rc1 Release Checklist so removing the "revisit" tag.

webchick’s picture

Issue summary: View changes
Status: Active » Needs review

Ok, attempting to update the issue summary based on recent comments.

There's a proposed resolution there now, so marking needs review.

xjm’s picture

Summary looks great to me, with one clarification/suggestion:

Migrate in core will be considered supported (and release-ready) when it is complete (both D6 and D7) #2456261: [META] Finalize the Migration system, including a UI with sound UX.

I think if the UI is complete with sound UX, and the D6 migration path is complete without any critical bugs affecting it, then we can provide UI support for only the D6->8 migration, since that's what's most important. The 7->8 migration path need not be complete to support 6->8, and could be shipped in a later minor.

catch’s picture

Yes as long as we can provide a UI for 6-8 and not 7-8, but have the 7-8 code in core to be worked on and tested, that sounds fine to me as well.

xjm’s picture

Issue summary: View changes

Talked to @webchick and updating the summary with this suggestion.

xjm’s picture

Issue summary: View changes

And adding in @catch's caveat from #29.

xjm’s picture

I spoke to Moshe a bit about this issue. He pointed out that he found the supported/unsupported distinction a bit confusing here, and also pointed out that no matter what we say there's still a bit of odd by having 8.0.0. considered "supported" except for certain code within it. He also suggested that we have a paragraph about the current support for Migrate (whatever it is) in the release notes.

I think this policy is mostly useful for core migrate contributors and release management, and less useful to end users. Not having a UI is the key thing I think for other audiences.

webchick’s picture

Currently, Migrate critical issues sit at 18, while Release critical issues sit at 12.

It remains to be seen which number will hit zero first, but there's at least a fairly realistic possibility that Drupal 8 will reach RC before we finish the migration system. If that happens, we need a "plan B" so that migrate doesn't hold up D8's release.

The core committers discussed this the other week, and one idea was to simply set hidden: true in the .info files of Migrate / Migrate Drupal if we need to resort to "plan B." (Migrate Upgrade could unset this value with hook_system_info_alter() or whatever.) This ensures the functionality (+ most importantly, tests) stays in core for those brave enough to use it (either by manually commenting those lines out, or by using Drush, or what have you) without exposing it to all site builders everywhere to give it a shot, when we know there are critical issues with it. We would obviously also prioritize this work heavily in 8.1.0.

Obviously, the preference would be to close out #2297213: [meta] Ensure that there are no critical Migrate issues before releasing the migration path and not have to pursue this at all, but at 3 weeks before Barcelona, now's the time to line up our ducks.

webchick’s picture

Another update from the core committer discussion w/ @Dries today.

Everyone across the board wants there to be as few blockers in the way of D8.0.0 as possible. And even if the Migrate UI is done in time for RC1 (it has a patch now, yay!), exposing it to site builders is sure to result in site builders actually testing it (damn it), and that in turn is sure to uncover critical bugs that we don't know about yet since migrations have been so hidden (which is why we want the UI), and critical issues are something which we do not need any more of. (Seriously. We've been hovering around 10-15 since mid-July.)

OTOH, the Migrate team has been kicking all ass for the past few weeks. is a great doc by @mikeryan that's tracking all the current blockers and crossing out things that are done. It would seriously suck if the Migrate team worked really hard and beat core in reducing their criticals to zero, only to be told their stuff was now on ice for 6 months until 8.1's release (even if it was the most important initiative for 8.1, which it would be).

Dries thought of what I think is a brilliant compromise, which is that if Migrate is ready before RC1, we would expose the Migrate Upgrade UI module to site builders, but mark the module as "Experimental" (Alex Pott suggested a dedicated module package for this, which makes great sense). The goal of 8.1 then would become moving that module from "Experimental" to just regular ol' core. We could also use that same "Experimental" pattern in other "more than 6 months but can be in a partially shippable state sooner" efforts we might want to do in the rest of the D8 cycle.


mikeryan’s picture

+1 from me - the migration path has not been tested on a wide variety of real-world sites yet, so going out in 8.0 as fully supported would be a little scary - I have no doubt there are many edge cases in both Drupal 6 and Drupal 7 sites that will give us trouble. Exposed so it is visible and does get tested, but "experimental" to set appropriate expectations, seems the perfect approach to me.

phenaproxima’s picture

+1 as well.

I doubt we'll have the full D6 and D7 migration paths 100% ready by RC1, but I do expect that D6 will be very stable and D7 will support, at a minimum, the "Big Four" (nodes, comments, users -- which are already supported! -- and taxonomy), plus a smattering of minor variable-to-config migrations. That said, migration is very tricky by nature and I agree that site builders are certain to find problems. (I don't think that real-world testing is likely to result in full-fledged criticals, but the possibility of Migrate-criticals is high.)

Making it visible, but experimental, is a perfect compromise -- cowboys and early adopters can bang on it, and more cautious folks can keep their distance. And it's a pattern that could be applied other "innovative" parts of core that aren't quite yet ready for prime time.

webchick’s picture

Assigned: Unassigned » benjy
Issue summary: View changes
Status: Needs review » Reviewed & tested by the community

Attempting to update the issue summary with what seems to have consensus so far, marking RTBC for better visibility. For sure we need benjy's 2 cents first, so assigning to him.

webchick’s picture

Issue summary: View changes

*(@$ing bendy quotes. :P

webchick’s picture

Issue summary: View changes
benjy’s picture

Assigned: benjy » Unassigned

Yeah this sounds good, +1 from me.

hass’s picture

Can someone put a note on #2532550: Leading slashes not added to visibility paths and weight if this is another critical?

From nitpicking point of view the migrated site will no longer show any blocks where they have been shown in past and this "destroys" an existing site. As this is a D6/D7 to D8 issue I think it should have a high priority, too. I think nobody like to fix all it's paths manually after a migration.

webchick’s picture

Status: Reviewed & tested by the community » Fixed

That might be another migrate critical (sounds like from the Migrate maintainers it's not; just a major bug), but I don't think that affects this policy in any way.

Ok, looks like Mike, Adam, and Ben are all on board, as well as the core committers.

Added a sub-page at (which is a sub-page of the main D8 migrate docs) with the information from the issue summary. Also spun off #2560597: Mark Migrate* modules as Experimental to mark the Migrate stuff as experimental until 8.1.0+.

Moving to fixed! Thanks a lot, all.

chx’s picture

Note: I do not think Drupal 7 => Drupal 8 issues should be tagged as "Migrate critical" .

catch’s picture

Hmm, we could have a new tag that is 'Migrate D7 critical'?

chx’s picture

Sounds like a plan.

webchick’s picture

Status: Fixed » Closed (fixed)

Automatically closed - issue fixed for 2 weeks with no activity.