I installed the latest version of the SW130 pdk (first time I installed it). There are 2 flavours: sky130A and sky130B. Which is used for the chipignite T/O and whats the difference between the two?

SKY130A used by ChipIgnite. If you're going to use Re-RAM in your design, then SKY130B variant should be used.

Makefile

has this setup to read automatically.

great. Txs

Can you get a ChipIgnite run with SKY130B and ReRAM?