Where can I change the canonical for home? Documentation doesn’t say a word about it of course, there are some instructions how to make it on products, but what about home page?
I see my canonical is wrong (sure it is, it is Shopware), finding myself the option in administration failed (sure it did, it is Shopware), internet also doesn’t seem to have the answer (sure it doesn’t, it is about Shopware). Does anyone know?
Not sure why your canonical is wrong. Works fine for me.
Okay dear friend, first of all, I am very happy that it works by you, that made my day that somewhere on some mysterious computer it works, it’s like I can go peacefuly home now. 
Secondly, did you just put here whole the meta.html.twig? Seriously? Wow…
At third, my question was „where do I set it“ so I can change it. Sure I see in the twig file where it is, but I need to remove the slash from the end of canonical. And this seems not only to be impossible to be done on the template itself, but it seems there is no option to ‚configure‘ how the canonicals should look like.
Also, have a look what happens when you try to do any string operation on the canonical, eg.:
{{ page.metaInformation.canonical[0:-1] }}
I am glad I could help you.
By the way of your thinking, aren’t you one of the guys who created and now mantain the Shopware?
No, I’m afraid I have to disappoint you. I only do this in my spare time.