The diff output is buffered in a FILE object and could still be partially buffered when we print these warnings (directly to fd 2). The output is messed up like this worktree.c | 138 +- worktree.h warning: inexact rename detection was skipped due to too many files. | 12 +- wrapper.c | 83 +- It gets worse if the warning is printed after color codes for the graph part are already printed. You'll get a warning in green or red. Flush stdout first, so we can get something like this instead: xdiff/xutils.c | 42 +- xdiff/xutils.h | 4 +- 1033 files changed, 150824 insertions(+), 69395 deletions(-) warning: inexact rename detection was skipped due to too many files. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx> --- diff.c | 1 + 1 file changed, 1 insertion(+) diff --git a/diff.c b/diff.c index fb22b19f09..5545c25640 100644 --- a/diff.c +++ b/diff.c @@ -5454,6 +5454,7 @@ N_("you may want to set your %s variable to at least " void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc) { + fflush(stdout); if (degraded_cc) warning(_(degrade_cc_to_c_warning)); else if (needed) -- 2.15.1.600.g899a5f85c6