I cast on and managed the whole first round of rib before frogging it. I’d messed up the pattern part way through the round. Also I wasn’t doing the ‘magic loop’ thing right, so everything was straining against the needles.
On the second try I managed to get about 8 rounds done and master the ‘magic loop’ on one circular needle. There was still one problem – even having allowed for knitting more tightly on circulars, the thing was too tight. The chenille won’t survive re-frogging. I was lucky to manage it once! Anyway, third time lucky tommorrow with fresh yarn.