Steve,
The report did not "rubbish" the Chakrabarti report.

Yes it did.
" The Chakrabarti report makes recommendations about creating a more robust disciplinary process within the Labour Party, but it is clearly lacking in many areas; particularly in its failure to differentiate explicitly between racism and antisemitism. The fact that the report describes occurrences of antisemitism merely as "unhappy incidents" also suggests that it fails to appreciate the full gravity of the comments that prompted the inquiry in the first place. These shortfalls, combined with Ms Chakrabarti's decision to join the Labour Party in April and accept a peerage as a nominee of the Leader of that Party, and her subsequent appointment as Shadow Attorney General, have thrown into question her claims (and those of Mr Corbyn) that her inquiry was truly independent. Ms Chakrabarti has not been sufficiently open with the Committee about when she was offered her peerage, despite several attempts to clarify this issue with her. It is disappointing that she did not foresee that the timing of her elevation to the House of Lords, alongside a report absolving the Labour Leader of any responsibility for allegations of increased antisemitism within his Party, would completely undermine her efforts to address this issue. It is equally concerning that Mr Corbyn did not consider the damaging impression likely to be created by this sequence of events. (Paragraph 114)"

It did not specify the antisemitism accusations in any detail

Of course not. There were hundreds!

and did not accuse Labour of widespread or institutional antisemitism.

No-one has claimed that anyway.

Jim,
"Accusations of unacceptable anti-Semitism, bullying, misogyny and homophobia "
None were described

NO, but we know that many accusations have been made, leading to two Labour and one Parliamentary enquiry and over 50 suspensions from the Party, so you can hardly deny them even if we do not have all the details ourselves.