If possible, can the diffutils package be updated to >= 3.0 please? (latest version is 3.2)
Among other fixes, the 3.0 version contains the following interesting improvement:
In context-style diffs, diff prints a portion of a preceding "function"
line for each hunk, with --show-function-line=RE (-F) or
--show-c-function (-p). Now, it trims leading blanks from such lines
before extracting a prefix. This is useful especially when a function
line is so far indented that the name itself would be truncated or not
included in the limited-width substring that diff appends.