logParser gives missing weights for LHE-only geneation

Reported by @xiaohu

Just to be 100% sure, we generate LHE files externally using Powheg-Box-V2. Weight variations due to PDF and scales are prepared. With checkMetaSG.py, we do see all the weights in evgen files (showered by Herwig7 with 21.6.12,AthGeneration) [1] and looked at the weight variations using truth derivation. But using logParser.py to check log.generate, it says “weights missing”.

Probably what happens is that the weights in logParser are read from lines that look like this: 09:33:22 MetaData: weights = MUR=0.5 MUF=0.5 | PDF=260000 MemberID=1
and for LHE-only generation this does not get written out.

Need to confirm and perhaps fix for LHE only generation