On Wed, May 12 2021, Xinglu Chen wrote:

>>> I am now bisecting commit 5866fa558b68b3e0213b9eef93d115e6e38dcc2a, I
>>> don’t think it should be related to the changes to the
>>> ‘emacs-build-system’.
>> The wip-ungrafting merge?
>
> Yup.

When bisecting commit 76b6c61609fd8352ce01059307cf1aec85b8d0df, the
‘graphviz’ package, which ‘emacs’ depends on, fails to build.