Migrating from v3.x to v4.x

[calculuschild]

I'm struggling to find any kind of migration guide on what breaking changes there might be between v3 and v4. Can someone point me in the right direction so I can upgrade smoothly? We use LESS pretty extensively and ferreting out all the possible changes is usually pretty tricky without any kind of guide or documentaton.

[iChenLei]

Maybe you can review less.js changelog and github releases

[matthew-dean]

@calculuschild The main change is the default from math: 'always' to math: 'parents-division'. This prevents evaluating math when using / as a valid CSS list separator.