DIY

The glue 'dries' clear and if you can do without your headphones for a while, the UV radiation in sunlight will do the trick, you just have to be patient. That is why most people use UV lights. Besides if you have the light, you can just put it aside until the next time you need it. I got a reeeeeal cheap one that is used for LOCA glue that they use for nail work to glue on decretive long fingernails but I used it for gluing LOCA adhesive for my cell phone screen protectors. Once you have it, take the battery out or insulate one side of it, and then you have it for the next time you need it. here is one like I used but there are a ton of cheap ones...(not an affiliate link)

https://www.aliexpress.com/item/1005008406384030.html

There is a JB Weld UV glue product that comes with a UV LED attached:

https://www.jbweld.com/product/superweld-light-activated

It's a blend, not pure UV resin, that will harden quickly where the light hits it but will also slowly cure without UV exposure, so the inner parts of the joint will harden over time.

I use this and I've found that it is almost as good as standard 2-part epoxy in most cases, and easier to use.

You can also cure UV glue in sunlight. It's a bit of a pain and can take longer, but it's an option.

If you're trying to be true to the "solarpunk ethos," do you really think this is the last repair you'll ever do?

I, for one, have never regretted letting a 'one time' project be an excuse to get a new type of tool.

(Just don't get the disposable UV light another reply mentioned; that really is a bit wasteful. If you decide to go the UV glue route, get an inexpensive but proper standalone UV flashlight.)