Thank you @atailouloute.

I think this should be reverted. It breaks laravel/framework's 7.x branch which depends on symfony/http-foundation: ^5.0. When v5.1.0 comes out, it will be broken. I'd argue Laravel was not using symfony/mime implicitly, since it called code in http-foundation. It didn't make use of a non-direct dependency by bypassing http-foundation code. I think Symfony should wait until 6.0 before making this an optional dependency.

// cc @taylorotwell

Is Laravel 7 released? I'd suggest explicitly requiring symfony/mime on your side.
This change is planned for Symfony 5.1, which is unreleased also.
Note that this change is not covered by the BC policy. We already did so in the past and will continue to when needed.
Note also that in some specific cases, we decided to postpone the removal of some deps to the next major. This was done only for convenience. Here, I think you have plenty of time to adapt and you should. The change is easy enough to do.

Laravel 7 will depend on ^5.0, which means once 5.1.0 is tagged, we'd have unexpected breakage.

What was more concerning is that this change might be wanted in a symfony 4.4 patch release?

#35807 (review)

Even if you add symfony/mime in your deps explicitly?

We should be fine once we do that. My objection was to the principal of such changes.

What was more concerning is that this change might be wanted in a symfony 4.4 patch release?
#35807 (review)

I missed the PR that made it optional recently, sorry. This is for master.

What was more concerning is that this change might be wanted in a symfony 4.4 patch release?

this won't happen, @chalasr must have been mistaken :)

We should be fine once we do that.

that's the way to go then, this change is desired on our side (to me at least.)

Ok. :)