(?m)applies the following effective flags to the remainder of the pattern: gm m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string
^start of line
\s*any whitespace character, repeated any number of times
!the literal ! (3310 / 418 / 2116)
\s+any whitespace character, repeated at least once
\[the literal [ (9110 / 1338 / 5B16)
Non-Capturing Group(?:remote )? ?repeats the group contents below at most once:
remote the literal text remote (case sensitive) rejected]the literal text rejected] (case sensitive) .+any character (except for line terminators), repeated at least once
\(the literal ( (4010 / 508 / 2816)
Non-Capturing Group(?:non-fast-forward|fetch first|cannot lock ref.*) 1st Alternativenon-fast-forward non-fast-forwardthe literal text non-fast-forward (case sensitive) 2nd Alternativefetch first fetch firstthe literal text fetch first (case sensitive) 3rd Alternativecannot lock ref.* cannot lock refthe literal text cannot lock ref (case sensitive) .*any character (except for line terminators), repeated any number of times
\)the literal ) (4110 / 518 / 2916)
\s*any whitespace character, repeated any number of times
$end of line
g modifier: global. Finds all matches instead of stopping after the first