Trying to upgrade to 1.2 and failing

I’m trying to upgrade from 1.1.0.3 but am failing, if I run meteor upgrade I get this:

Update to release METEOR@1.2 is impossible:
While selecting package versions:
error: Conflict: Constraint less@1.0.11 is not satisfied by less 2.5.0_1.
Constraints on package "less":
* less@=2.5.0_1 <- top level
* less@1.0.11 <- useraccounts:semantic-ui 1.8.1
* less@2.5.0_1 <- accounts-ui 1.1.6
* less@2.5.0_1 <- accounts-ui-unstyled 1.1.8 <- accounts-ui 1.1.6

So I try upgrading useraccounts:semantic-ui which just gives me Your packages are at their latest compatible versions.

How can I proceed from here? Do I have to go through every single package I’m using and try and upgrade them individually in the hopes that version solver then passes? Or is there a way to see things in more detail so I know what needs updating first?

You could try forcing the Semantic upgrade:

meter add useraccounts:semantic-ui@1.12.4